UNITED STATES OF AMERICA. 




c^^^ls^ 



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CHEMISTRY FOR FAR3IERS. 



THE 



ELEMENTS of CHEMISTRY 



AS APPLIED 



TO AGRICULTURE. 




By C. B. chapman, A. M., M. D., 

PROFESSOE OP CHEMISTRY. 



PUBLISHERS: 
CINCINNATI— WINTHROP B. SMITH & CO. 



Entered, according to Act of Congress, in the year Eigliteen Hundred and Sixty, 
by C. B. Chapman, in the Clerk's Office of the District Court of the United 
States, for the Southern District of Ohio. 

STEREOTYPED AT THE FRANKLIN TYPE FOUNDRY, CINCINNATI, 0. 



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1 



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1^ 

PREFACE. 



The importance of placing before the youth in our schools, as 
well as in the hands of our farmers at their homes, the means 
of acquiring a knowledge of the elements of the science and art 
of agriculture, has long been acknowledged by teachers and 
others. 

Such means have already been available to those who had 
acquired a limited knowledge of chemistry ; but the most valuable 
works, containing the facts most useful to the practical farmer, 
have been too voluminous and expensive for his own use and 
means, or too technical for the use of his sons while in the common 
schools. 

The material which is offered in this treatise, is the result of 
considerable practical observation, and has been used by the 
author, in his lectures to classes, during several years of pro- 
fessional labor. 

The improvement which was apparent in these classes, has 
encouraged him to believe that the same materials might be used 
with advantage and profit by teachers and pupils in public 
schools, especially in those districts where the people are gener- 
ally engaged in agricultural pursuits. 

The day has gone by when farmers were esteemed the most 
ignorant among citizens, and it is now held absolutely necessary 
for success, as well as indispensable to proper social standing, 
that farmers should be educated thoroughly in their calling. 

If the author shall have contributed anything to aid the farmer 
in his important work, or to furnish for young men who are look- 
ing forward to this vocation, the means of more thorough prepa- 
ration for their honorable and useful calling, his object in giving 
to the public this unpretending volume will be attained. 

(iii) 



CONTENTS 



PAGE 

Introduction 7 

CHAPTER I. 

TABLE AND SYNOPSIS OF ELEMENTS. 

Table of Elements 11 

CHAPTER II. 

UNION OF ELEMENTS FORMING COMPOUNDS; NOMENCLATURE AND 
SYMBOLS. 

Table of Compounds of Nitrogen and Oxygen — Cohesion and 
Affinity Table, shoi;?ing Affinities 14 

CHAPTER III. 

AGRICULTURE DEFINED. 

Mechanical Agriculture — Scientific Agriculture 20 

CHAPTER IV. 

MATERIALS OF WHICH SOILS ARE COMPOSED. 

Organic Elements — Inorganic Elements — Inorganic Com- 
pounds — Potash — Soda — Lime — Magnesia — Silex or Silica 
— Chlorine — Phosphoric Acid — Sulphuric Acid — Oxide of 
Iron — Oxide of Manganese — Aluminum — Fluorine 22 

CHAPTER V. 

ORGANIC ELEMENTS. 

Carbon — Diamond — Charcoal — Anthracite Coal — Bituminous 
Coal — Graphite — Coke — Nitrogen — Oxygen — Hydrogen — 

Philosopher's Lamp 32 

(iy) 



CONTENTS. V 

PAGE 

CHAPTER VI. 

COMPOUNDS PRODUCED BY DECOMPOSITION OP ORGANIC MATTER. 

Water — Carbonic Acid — Ammonia 42 

CHAPTER VII. 

MATERIALS OF WHICH PLANTS ARE COMPOSED. 

Carbon — Nitrogen or Azote — Hydrogen and Oxygen 47 

CHAPTER VIII. 

INORGANIC COMPOUNDS IN PLANTS. 

Potash — Soda — Lime — Magnesia — Phosphoric Acid — Sulphu- 
ric Acid — Silica — Oxide of Iron — Oxide of Manganese 48 

CHAPTER IX. 

ORGANIC COMPOUNDS IN PLANTS. 

Woody Fiber— Starch— Gluten 50 

CHAPTER X. 

SUBSTANCES FORMED MOSTLY OF CARBON. 

Woody Fiber — Starch — Gum — Sugar — Oil 62 

CHAPTEPv XI. 

THE ATMOSPHERE. 

Atmospheric Air — Uses of Nitrogen — Impurities — How sup- 
plied to the Atmosphere — Proportion of Carbonic Acid 63 

CHAPTER XII. 

FORMS IN WHICH NUTRIMENT IS RECEIVED BY PLANTS. 

Power of receiving Inorganic Materials — Important Offices of 
Leaves 65 

CHAPTER XIIL 

SOURCES OF NITROGEN. 

Ammonia — Carbonic Acid — Water 56 



y[ CONTENTS. 

PAOE 

CHAPTER XIV. 

MATERIALS OF WHICH SOIL IS COMPOSED. 

Inorganic Matter' — Peaty Soils •. 58 

CHAPTER XV. 

SOURCES OF THE INORGANIC PARTS OF SOIL. 

Rocks which form Soils — Sandstone — Limestone — Marble — 
Chalk— Slate CO 

CHAPTER XVI. 

CLASSIFICATION OF SOIL. 

Sandy — Clayey — Calcareous — Loamy — Marly 63 

CHAPTER XVII. 

MANURES. 

Farm-yard Manure — Animal and Vegetable Manures — Green 
Grass and Clover — Flesh of Animals — Dead Fish — Guano — 
Night Soil — Poudrette — Poultry-house Manure — Hay Ma- 
nure — Sheep Manure — Bones — Charcoal — Soot 65 

CHAPTER XVIII. 

INORGANIC MANURES. 

Gypsum — Quick-Lime — Salts — Action of Lime upon Organic 
Substances — .Action of Lime upon Inorganic Compounds — 
Chloride of Lime — Phosphate of Lime — Bone-black 75 

CHAPTER XIX. 

DRAINAGE. 

Surplus Water— Shafts— Clay— Protoxide of Iron 88 

APPENDIX. 

Directions for using Apparatus - 95 

Directions for Experiments 96 

Analysis of Manures and Crops 103 

Glossary........ Ill 



INTRODUCTION 



In order to understand the first principles of agricul- 
ture, as a science, it is necessary that some of the simple 
lessons in chemistry should be learned ; and these are best 
taught in the same manner as the elements of that science 
are presented in the common text-books. 

There is no royal road to knowledge in any department 
of science, although the avenues to these acquirements may 
be greatly improved by the adoption of a well-adapted ar- 
rangement of lessons ; and to make the best use of these 
lessons, it is necessary that a small amount of apparatus 
should be used; but the arrangement of illustrations is 
such, that this is not indispensable to their profitable use 
in the school-room. 

Teachers may too often be deterred from -the attempt to 
use apparatus, for illustrating their lessons, on account of 
not having tested their ability to do so. Such may be 
assured, that, with proper care in observing the directions 
given, for the purpose of aiding teachers in their first 
attempts, they Vv^ill be surprised to discover the facility with 
which they will succeed. 

There are some principles, or facts, in agriculture, which 
apply peculiarly to each country or locality ; but these are 

(') 



8 INTRODUCTION. 

found iMCKstly to apply to tlae mechanical condition of soils ; 
and such as are remedied by drainage, pulverization, 
and MIXTURE with substances which will render the ar- 
rangement of its particles such as to subserve the uses of 
the plant we propose to raise. 

There are other principles which apply alike to all 
countries and localities ; for each plant, as well as each 
animal, requires certain elements as food, or material out 
of which their tissues are constructed. 

The first scientific facts, or principles, in agriculture, are 
few and extremely simple ; but it is no less important that 
they should be thoroughly acquired, than that one who 
proposes to learn a language, should, first of all, become 
familiar with its alphabet. 

Many persons, already engaged in agricultural pursuits, 
have, most likely, been deterred from the eff"ort to acquire 
these first principles, by the belief that more time would 
be required for its accomplishment, than would be compat- 
ible with their other avocations. 

It has been the aim of the author so to condense the 
statement of the facts which are involved in the chemistry 
of this art, that the work might be adapted, not only for 
use in the school-room, but for fireside perusal, and thus 
furnish the means for rendering our young farmers as well 
versed in the science which belongs to their chosen pursuit, 
as those of any other country. 

The farmer has too often been led to believe that his 
experience is worth more to him than those aids which he 
can derive from science ; but such persons should be aware, 
that to become familiar with the principles of the science 
upon which his art is based, can most surely do him no 



INTEODUCTION. 9 

barm, and will, at least, enable him to judge more correctly, 
with regard to the value of his experiences when thus 
compared. 

^ The wealth of the merchant is increased, only by the 
well-directed employment of his capital. On the same 
principle, the wealth of the farmer is mostly augmented 
by the best use of his grounds ; and this consists in adapt- 
ing his crop to the present condition of his field, so that 
when defective, he supplies such manures as are best cal- 
culated to improve the crop he proposes to raise. ^ 
' In some instances, instead of furnishing manure to his 
field, he may introduce such crop as can be sustained by 
materials which the soil already contains. ^' 
V Soil and manure, in a certain sense, are the farmer's 
capital ; and while manures are cheap, and often furnished 
without the outlay of capital, especially when their nature 
is understood, the crops which they contribute to improve 
are sold for a considerable sum. That which was cheap, 
and in some instances worthless, is, by the processes of the 
farmer, converted into that which is valuable. 

This is the only rational basis on which the farmer is 
enabled to estimate the value of his capital, and his only 
sure guide in selecting the best methods for its employ- 
ment. A superabundance of food is no more useful for a 
plant than for an animal; and consequently nothing is 
gained by adding a substance as a manure which already 
exists in sufficient proportion in a soil. / 

There is no common material in soils, the use of which 
the farmer is more interested in properly understanding, 
than lime. This substance, when artificially used in its 



10 INTRODUCTION. 

various combinatious, may be employed to correct any 
excess, eitber of alkalies, or of acids ; in accordance with 
the nature of tbe elements which enter into the formation 
of the article employed. 

The tests for determining the presence, and excess, of 
either alkalies or acids in soils, are so simple, and so easily 
applied, that they may be used by the farmer without seek- 
ing an analysis by the practical chemist, although a care- 
ful analysis, which will reveal the exact materials of which 
his soil is composed, will often be a most useful invest- 
ment for him, although attended with some expense. 

For determining the presence of acids, or alkalies, he 
has only to employ two common substances, which will be 
found in the shops. These are an acid (sulphuric, or chlo- 
rohydric) for determining the presence of an alkali, or an 
alkali (ammonia), to test the presence of an acid. 

By ascertaining whether a soil contains an acid or an 
alkali, in excess, the farmer may save the unnecessary 
expenditure of much time and labor, as well, perhaps, as 
of a costly manure ; for it has too often been true, that as 
to their constituents, manures have been applied indis- 
criminately, whenever a soil has been found unequal to 
the production of a crop. This is but a simple example 
of the value of chemical knowledge to the farmer, and 
shows how easily and cheaply tests which may reveal fiicts 
of great practical utility, may be employed by every 
farmer. 



AGRICULTURAL CHEMISTRY. 



CHAPTER I. 

TABLE AND SYNOPSIS OF ELEMENTS. 

The language used in works on chemistry possesses 
peculiar advantages, in its brevity by the use of symbols, 
thus presenting to the eye, in a simple familiar operation 
and results, the description of which would otherwise con- 
fuse the mind by its length and complexity. 

The whole number of elementary substances is but fifty- 
nine. 

An elementary body is one which can not by any known 
process, be divided, and thus made to assume different 
forms. AVater, although it appears to us as a simple 
body, may be analyzed by processes which are easily prac- 
ticed by the chemist, and thus resolved into the two ele- 
ments of which it is composed. 

These elements are oxygen and hydrogen gases, neither 
of which can be again subdivided, but can be made to 
unite with still other elements, and thus produce other 

"What means are used to express the language of chemistry? 
What is the number of elementary substances ? 

What is an elementary body? Of how many elements is water 
composed? What are they ? Can either of these be again divided? 
Will they unite with other elements? 

(11) 



12 AGRICULTURAL CHEMLSTRY. 

compounds, wliich will be found to possess none of the 
properties of tlie original elements of which the body is 
composed. 

It has been discovered, that when elements unite among 
themselves, it is invariably in certain fixed proportions, or 
weights, or their multiples. 

Water is composed of oxygen and hydrogen, which are 
here united in quite dijQferent degrees of weight and bulk, 
for the weight is in the proportion of one of hydrogen to 
eight of oxygen, while the hydrogen, when free, will occupy 
twice the space of the oxygen ; or a given bulk of oxygen 
will weigh sixteen times as much as the same bulk of 
hydrogen. 

As hydrogen is found to unite with other bodies in a 
smaller weight than any other known element, it has been 
commonly adopted as the basis of unity of the scale of 
equivalent numbers. 

In the following table, hydrogen is represented by the 
figure one, and the combining or atomic weight of each of 
the other elements, are rated in proportion from this 
number. 

The symbols are expressed by the first, or the first and 
one other letter of the name of the elements, and the 
atomic weight is represented in the right hand column. 

Will compounds produced by such union possess any of the 
properties of their original elements? In what way do elements 
unite ? 

In what proportions, by weight, are the elements of water 
united? In what proportions by bulk? 

What element is adopted as the basis of unity of the scale of 
equivalent numbers ? What figure represents hydrogen ? 

How are symbols expressed? Where is the atomic weight 
represented ? 



TABLE AND SYNOPSIS. 



13 



\^TaJ)le of the whole number of Jcnoivn elements.'] 



Aluminum 

Antimony (stibium) 

Arsenic 

Barium 

Bismuth 

Boron 

Bromine 

Cadmium 

Calcium 

Carbon 

Cerium 

Chlorine 

Chromium 

Cobalt 

Copper (cuprum) 

Didymium 

Fluorine 

Glucinum 

Gold (aurum) 

Hydrogen 

Iodine 

Iridium 

Iron (ferrum) 

Lanthanum 

Lead (plumbum) 

Lithium 

Magnesium 

Manganese 

Mercury (hydrargy- 
rum) 

Molybdenum . 



Al. 


13.69 j 


Sb. 


129.03 


As. 


Y5 


Ba. 


68.64 


Bi. 


70.95 


B. 


10.90 


Br. 


78.26 


Cd. 


55.74 


Ca. 


20 


C. 


6 


Ce. 


46 


CI. 


35.50 


Cr. 


28.15 


Co. 


29.52 


Cu. 


31.66 


D. 


49.6 


F. 


18.70 


Gl. 


26.50 


Au. 


98.33 


H. 


1 


T. 


126.36 


Ir. 


98.68 


Fe. 


28 


Ln. 


48 


Pb. 


103.56 


Li. 


6.43 


Mg. 


12.67 


Mn. 


27.67 


Hg. 


100.07 


Mo. 


47.88 



Nickel 

Niobium 

Nitrogen, or Azote.,. 

Osmium 

Oxygen 

Palladium 

Pelopium 

Phosphorus 

Platinum 

Potassium (kalium). 

Rhodium 

Ruthenium 

Selenium 

Silicium 

Silver (argentum)... 
Sodium (natronium) 

Strontium 

Sulphur 

Tentalium or Colum- 

bium 

Telurium 

Thorium 

Tin (stannum) 

Titanium 

Tungsten (wolfram) 

Uranium 

Vanadium 

Yttrium 

Zinc 

Zirconium 



Ni. 29.57 



Ta. 
Te. 
Th. 

Sn. 
Ti. 

w. 

u. 

V. 
Y. 
Zn. 
Zr. 



iN.or 
Az. 


14 


Os. 


99.56 


0. 


8 


Pd. 


53.27 


P.'"' 


*32.'02 


Pt. 


98.68 


K. 


89.00 


R. 


52.11 


Ru. 


52.11 


Se. 


89.57 


Si. 


21.35 


Ag. 


108 


JNa. 


22.97 


Sr. 


43.84 


s. 


16 



92.80 

66.14 

59.59 

58.82 

24.29 

94.64 

60 

68.55 

32.20 

82.52 

88.62 



Three others* have been referred to in some works, but 
these are of still less importance than any of those con- 
tained in the table. 

These are Erbium, Norium, and Terbium. 

Only fourteen elements are common, either in the com- 
position of the EARTH, WATER, or ATMOSPHERE. Enumer- 
ated with these are two others, bul they exist in very small 
quantities, as constituents of soils. 

How many elements are common in the earth, water, and atmos- 
phere? What others exist in small quantity in soils ? 

* Graham's Elements of Chemistiy. 



14 AGRICULTURAL CHEMISTRY. 

When set free, and at common temperatures, mucli tlie 
largest number of the elements are solids. Five are gases, 
namely: Oxygen, Nitrogen, Hydrogen, Chlorine, and 
Fluorine. Mercury and Bromine, only, are fluids. 

Some of the elementary bodies exist free in nature, and 
were known long before the science of chemistry had im- 
parted a knowledge of their true character and relations. 
Among these were several of the metals, as Iron, Copper, 
Gold, Silver, Mercury, Lead, and Tin. 

Others, as Potassium, Sodium, Calcium, Magnesium, 
as well as the largest number of common substances, are 
found in nature only in combination with other elements, 
the principal of which is oxygen. 



CHAPTER II, 



UNION OF elements FORMING COMPOUNDS; NOMENCLA- 
TURE AND SYMBOLS. 

The union of two or more elements produces a com- 
pound, and such compound commonly derives its name 
from the original substances of which it is composed. The 
materials which enter into the formation of a compound 

In what condition are the largest number of elements found ? 
How many are gases ? How many are fluids ? 

Do some exist free in nature ? Which have long been known ? 
Combined with what are the largest number found ? 

What does the union of two or more elements produce? Whence 
does such compound derive its name? 



NOMENCLATURE AND SYMBOLS. 15 

may be most easily expressed by a language of symbols. 
Such would by no means be true, if the number of origi- 
nal elements were equal to that of the compounds which 
they contribute to form. 

The whole number of elements is but fifty-nine, and, 
consequently, the symbols which are used to express these 
elements can only, correspond to that number. When 
more than one atom of a given elemeiit enters into a 
compound, such additional atoms are commonly expressed 
by a small figure at the right of the symbolic letter. 
Thus, CO2. 

The number of elements which will be described in 
this work is but sixteen, and two of these need be but 
briefly considered as elements connected with the organ- 
ization of living beings. No more than sixteen symbols, 
then, will be used in expressing these elements. 

Example. — Carbonic acid being composed of two ele- 
ments, carbon and oxygen, and the proportion of these 
being one of carbon, and two of oxygen, this compound 
gas is thus expressed in symbols, CO2. 

As the equivalent number for carbon is 6, and that for 
oxygen is 8, it would be one of carbon, 6, and two of 
oxygen, twice 8 — or the whole would be expressed in 
figures, when added together, by 22, 

How may such materials be most easily expressed? Would this 
be true if the number of elements was equal to that of the com- 
pounds which they form ? 

To what does the number of symbols correspond ? When more 
than one atom of an element, how expressed ? 

What number of elements are described in this work? Then, 
how many symbols are used in it? 

Of what elements is carbonic acid composed? How many atoms 
of carbon? How many of oxygen? 

How is carbonic acid expressed in symbols? 



16 AGEICULTURAL CHEMISTRY. 

No figure is used when there is but one atom of an 
element; for the symbolic letter is understood to stand, 
not only for the element, but for one atom of the ele- 
ment. 

Elements unite with each other in fixed and invariable 
proportions, and the figure on the right of the symbol in 
the table of elements, always represents these proportions. 

If more than one equivalent of any given element unites 
with another, it is never united in parts, but in another 
whole equivalent proportion. 

Example. — Water is composed of one equivalent, or 
atom, each, of oxygen and hydrogen, and is expressed in 
symbols thus, H 0. 

Nine pounds of water are composed of one pound of 
hydrogen and eight pounds of oxygen. 

BiNOXiDE OF HYDROGEN is formed of one equivalent 
of hydrogen, and two of oxygen, and is expressed in 
symbols thus, H 2 . 

Seventeen pounds of binoxide of hydrogen are, conse- 
quently, found to be composed of one pound of hydrogen, 
and sixteen pounds of oxygen. 

A combination of two elements will produce a third 
substance, entirely unlike either of the original elements 
of which it is composed, and when the proportion of ele- 
ments is different, the product will also vary, both in 
properties and appearance. 

Is a figure used when there is but one atom of an element? 

Do elements unite with each other in invariable proportions? 
How is water expressed in symbols? 

How binoxide of hydrogen? Of how many pounds of each are 
seventeen pounds of binoxide of hydrogen composed ? 

Does the union of two elements in different proportions always 
produce a different substance? 



NOMENCLATURE AND SYMBOLS. 17 

The union of two elements in dilQferent proportions will 
produce entirely dijffcrent substances. The uu^on of one 
atom of oxygen and one of hydrogen, will produce water, 
and nothing else. The union of one equivalent of hydro- 
gen and two of oxygen, wdll form binoxide of hydrogen, 
a substance which will not possess any of the properties 
of water. 

A good illustration of the change in the character of 
substances, as influenced by variation in the number of 
equivalents of elements which compose them, may be 
obvserved in those entirely different compounds which are 
formed of oxygen and nitrogen, the two elements which 
compose the atmosphere. These two elements are not 
chemically combined in the formation of the atmosphere, 
but their particles float in relation with each other by that 
method w^hich is properly called mixture. 

The chemical combinations of these elements are five in 
number, and are expressed by the following symbols : 

Protoxide of Nitrogen, NO. 

Deutoxide of Nitrogen, N O2. 

Hyponitrous Acid, N O3, 

Nitrous Acid, N O4. 

Nitric Acid, N O5. 

The first two of these are properly called oxides, and 
exist in the form of gases. 

Does the union of like atoms always produce a like substance? 
Give two examples. Of what two elements is the atmosphere 
composed? 

Are these chemically combined ? What is the number of chem- 
ical combinations of nitrogen and oxygen? What are the two 
first called ? 
2 



18 AtiPJCULTUIiAL CHEMISTRY. 

The lirst (protoxide of nitrogen, NO) can be inhaled 
by the lungs, when it produces a peculiar exhilarating 
effect, which has given it the common name of laughing 
gas. 

The second, (deutoxide of nitrogen NO 2,) although a 
gas, can not be received into the air passages ; for it excites 
a violent spasm in the larynx, when an attempt is made 
to inhale it. 

The last three are acids, and exist in the liquid form ; 
but their properties, and the purposes which they serve, 
are quite different. 

Hyponitrous acid, NO3, is a thin liquid. At common 
temperatures its color is green; but, when cooled down to 
zero, it becomes quite colorless. 

Nitrous acid, NO4, when at a low temperature, is a 
colorless liquid; but it becomes yellow as the temperature 
rises. 

Nitric acid, NO5, is the only one of these five com- 
pounds which is of any special importance in the arts. 

This powerful acid was first known some time in the 
ninth century, and with its discovery may be regarded the 
beginning of a knowledge of chemistry. It was long 
known as aqua forth, which name it bore on account of 
the great power which it possesses of acting upon, and 
uniting with, most of the hard metals. 

Its corrosive action upon all animal and vegetable 
(organic) substances, is immediate, and very powerful. 

What are the properties and effects of the first? What of the 
second? What are the last three properly called? 

What symbols express each of these? Which of these is of 
especial importance in the arts? 

What was its early name? Why this name? 



nome:n-clature and symbols. 19 

COHESION AND AFFINITY. 

The attraction of cohesion is understood to be that force 
which retains particles of a. like kind, "with various 
degrees of tenacity," in relation with each other, as the 
particles of a mass of metal, of which gold, silver, iron, 
and lead, may be taken as examples. 

The attraction of affinity^ in chemistry, is that union of 
substances which takes place between two elements, or 
bodies, which are unlike in their properties, in order that 
they may unite, and form a compound. 

This change takes place between such substances only 
as are quite diverse in their character, as an acid and an 
alkali. 

When an acid unites with an alkali a union takes place 
between them, and a third substance is produced. Such 
compound is entirely different from either of the original 
substances, both in appearance and in general properties. 
The product of such union is called a salt. 

The tendency to union between any given alkali, and 
the different acids, is quite unlike. 

Example. — If the alkali selected be soda, the tendency 
to union, or to remain united, which indicates the strength 
of affinity, is indicated by the following table, soda being 
the alkali used in the experiment : 

Soda, as the alkali, or base, 
Sulphuric acid. 
Nitric acid, 

What is the attraction of cohesion? What that of affinity? 

What does the union of an acid and an alkali produce? Is the 
tendency to union between any alkali and the different acids 
alike ? 



20 AGKICULTURAL CHEMISTRY. 

Cliloroliydric acid, 
Acetic acid, 
Carbonic acid. 

Those which most strongly resist separation from the 
base are found at the top of the table, and others are 
placed in succession, in accordance with their strength of 
affinity for the alkali. Thus : sulphuric acid may be used 
to secure a resolution of the union which exists between 
the soda, and any of the acids which are placed below 
them in the table. 



CHAPTEE III. 

AGRICULTURE DEFINED. 

/ The oldest, the most universal, as well as the most 
indispensable of human employments, is agriculture. 

Upon the practice of this art not less than eight hun- 
dred millions of human beings depend for their daily 
sustenance, and about eight-tenths of the inhabitants of 
the globe expend in it their daily labor. Something like 
two hundred millions of the inhabitants of the world sub- 
sist on such products of the earth as do not require the 
skill of husbandry. 

In the earliest periods of the world's history the prac- 

Narae the order of affinity between soda and the five acids 
mentioned. 

Where, in the table, is the acid which has the strongest affinity 
for soda placed ? 

Which is the oldest of employments? 



AGRICULTURE DEFINED, 21 

tice of agriculture was confined to the raising of a few- 
kinds of grain, and the care of herds of cattle. 

To the art of agriculture belongs a knowledge of the 
best methods of putting the seed for the various crops 
into the ground, of attending to them during the period 
of growth, of harvesting them at the proper time, and 
storing them away for future use, or preparing them for 
market, and each of these with the smallest expenditure 
of time and labor. 

The methods by which these operations are performed 
embrace what is called mechanical agriculture. 

Another department, which must be understood in order 
to the most economical pursuit of agriculture, involves a 
knowledge of the elements of which the plant is com- 
posed, of the soil from which it grows, and of the various 
manures which are used to enrich the soil, or to furnish 
food for plants. 

This is called scientific agriculture. 

Agriculture is pursued, then, both as a science and as 
an art. 

In no country have mechanical devices which are in- 
tended to save the time and labor of the farmer, been 
more extensively introduced than in the United States. 

The applications of science to agriculture have, how- 
ever, been more carefully studied, and are understood by 
a larger proportion of agriculturists in the countries of 
Europe, especially in Great Britain, France, Ger- 
many and Belgium, than in the United States. 

What belongs to this art? In how many divisions is agriculture 
studied? What ai'e they? What is mechanical agriculture? 

Where is mechanical agriculture best understood? Where 
scientific? 



22 AGRICULTURAL CHEMISTRY. 

This knowledge is more necessary for tlie inhabitants 
of those countries, on account of the numerous popula- 
tion, for which a limited amount of land must furnish 
subsistence. 

For this reason, in China the skillful cultivation of the 
soil is still more demanded than in any other country. 

An acquaintance with both mechanical and scientific 
agriculture is necessary to enable the farmer to raise the 
largest crop with the least possible injury to the soil, the 
smallest expenditure of time and labor, and the most 
economical investment of capital. 



CHAPTER lY. 

MATERIALS OF WHICH THE EARTH IS COMPOSED. 

Although the number of elements which compose the 
EARTH, AIR, and WATER, as well as the animals which 
exist on the globe, and the plants which grow from its 
surface, are but fifty-nine : only sixteen of these are known 
to form any considerable portion of the whole mass of 
which they are severally composed. 

ORGxVNIC ELEMENTS. 
Four of this number enter principally into the forma- 
tion of plants and animals, and are therefore distinguished 

Why is this knowledge more necessary in European countries? 
Where still more demanded? Why is a knowledge of both me- 
chanical and scientific agriculture required? 

How many elements form any considerable portion of the crust 
of the earth — of air, water, and plants ? 



MATERIALS COMPOSING EARTHS. . 23 

as ORGANIC ELEMENTS. Tliese are Carbon, Nitrogen, 
Oxygen, and Hydrogen. 

The other twelve exist in much smaller proportions in 
organized substances, but enter largely, though in very 
different proportions, into the formation of the crust of 
the earth. 

These are Potassium, Sodium, Magnesium, Calcium, 
Sulphur, Chlorine, Fluorine, Phosphorus, Silicium 
or Silicon, Aluminum, Manganese, and Iron. 

Ten substances, which are mostly compounds with 
oxygen, form the principal inorganic constituents of soils. 

These are Potash, Soda, Lime, Magnesia, Silica, 
Chlorine, Phosphoric acid. Sulphuric acid, Oxide 
op Iron, and Oxide of Manganese. 

The first four of this group are called alkalies, and 
may be distinguished by a peculiar taste, called alkaline^ 
as well as by their power to restore vegetable blues, when- 
ever they have been changed to red, by the action of an 
acid upon them. 

POTASH 

Is the strongest of the alkaline substances. 

It acts so powerfully upon the flesh of animals, and 
upon green vegetables, as to decompose them in a few 
liours. In the form in which it is commonly found in 

How many organic elements proper? What are they? What 
are the other twelve? 

How many substances form the principal inorganic constitu- 
ents of soils? With what are they mostly compounds? 

What are they? How many and which are alkalies? What 
distinguishes an alkali ? 

How is potash distinguished? How does it affect animal and 
vegeta^ile matter.' 



24 AGEICULTURAL CHEMISTRY. 

the shops, it is a white substance; and, unlike others of 
the same class, when exposed to the air, it absorbs much 
moisture, by which it becomes soft, and finally nearly 
liquid. 

Potash is obtained by dissolving the soluble portion 
of wood ashes, and evaporating the solution by boiling, 
when it remains in the vessel as a hard mass. 

In this form it is used in the manufacture of soap, 
which is formed by its combination with oil. It is also 
used in the manufacture of glass, in which process it 
must be intensely heated with silex. 

Potash exists naturally in^ some soils, especially in 
those latitudes where the successive growth and decom- 
position of such plants as contain large quantities of it 
succeed each other with great rapidity. 

When potash is exposed to an atmosphere which con- 
tains carbonic acid, it absorbs a portion of that gas, and 
is converted into carbonate of Potash^ or Pearl ash. This 
is expressed in symbols K 0, C O2. 

When another atom of carbonic acid is absorbed, it 
produces a bicarbonate of Fotash, or saleratus ; which 
is expressed by K 0, 2CO2. 

Potash unites with silica, and forms silicate of pot- 
ash. This compound is readily dissolved in water, by 
which it is enabled to circulate through the vessels of 

What is its appearance? How affected by moisture? How is 
potash obtained? 

For what purpose used in the arts? What combined with to 
form soap? To form glass? 

Where does potash exist naturally? What takes place when 
potash is exposed to an atmosphere which contains carbonic acid? 

What when another atom of carbonic acid is absorbed? What 
does potash and silica form ^ 



MATERIALS COMPOSING EARTHS. 25 

plants. This is tlie principal source from which silex is 
furnished to growing plants. 

SODA 
Is a white, crystalline substance, which, unlike potash, 
remains dry when exposed to the atmosphere. It was 
formerly manufactured from the ash of sea-weeds, or kdp^ 
but is now mostly produced from sea water, where it 
exists in combination with chlorine, which union forms 
CHLORIDE OF SODIUM, or common culinary salt. 

The principal difference in the soda produced from 
these two sources, is, that iodine exists in the ash of 
plants which grow in sea water. 

Soda, like potash, is used in the manufacture of soap 
and GLASS. 

The most common forms in which soda is found in the 
shops is a carbonate and bicarbonate. Another common 
form is the sulphate, which is commonly known as glau- 
ber salts. 

LIME 
Exists in nature in great abundance in combination 
with carbonic acid, or as a CARBONATE. The forms of 
carbonate of lime are three in number ; and, although 
composed of the same elements, their appearance is quite 
different, and their uses are- equally diverse. 

These forms are as LIME ROCK, marble, and chalk. 

For what is this used by plants? Describe soda. From what 
was it formerly manufactured? From what now manufactured? 
What is common salt? AVhat in addition does kelp contain? 

For what is soda used in the manufactures and arts? In what 
form is it most commonly found in sliops? 

In what form is lime mostly found? What are the forms of 
carbonate of lime ? 

3 



26 AGRICULTURAL CHEMISTRY. 

Nine-twentietlis of tlie weiglit of lime rock is dimin- 
ished by the aj^plication of heat, as in the common lime- 
kiln. 

By this j^rocess the carbonic acid which it contains is 
driven off into the atmosphere, where it constantly exists, 
in the proportion of four parts to ten thousand. The 
portion that remains in the kiln is quick-lime. 

When water is poured upon quick-lime, or when it is 
exposed to the atmosph-ere from which it absorbs water, 
heat is evolved; and this corresponds with the amount of 
water which is absorbed in a given time. As soon as 
heat becomes apparent, the lime crumbles to a powder, 
increases rapidly in weight, and assumes a form which is 
called the hydrate of lime. 

When further exposed to the atmosphere, carbonic acid 
is absorbed, and the mass gradually returns to the con- 
dition of a carbonate of lime. 

Lime also exists in nature as a sulj^hate ; and in this 
form is commonly known as gypsum, or plaster. When 
the -^ater which it contains has been expelled by heat, it 
forms a material which is used for stucco and plaster 
CASTS, and when thus prepared is known as Plaster of 
Paris. 

The fine, white, and variegated varieties, are called 
alabaster. 

How much is lime rock diminished in weight, in the lime-kiln? 
What is driven off? What is left? 

What proportion of carbonic acid exists in the atmosphere? 
What takes place when water is poured upon lime? What effect 
upon its condition and weight ? What is it then called ? 

What takes place when further exposed to the atmosphere? 
In what other form does lime exist in naiure? What are the 
hue, white, and variegated vHvieties called? 



MATERIALS COMPOSING EAETHS. 27 

MAGNESIA 
Is abundant in nature in many rocks, in union with 
lime, where it takes the name of magnesian lime rock. 
Magnesia is found in the shops in three forms : in a 
very light white powder, as a calcined magnesia; in 
irregular lumps, but also very light, as a carbonate; 
and in union with sulphuric acid, forming a salt, which 
is called a sulphate, or Epsom Salts. 

SILEX, 
Or Silica, is formed by the union of oxygen with 
Silicium or Silicon, and is commonly known as RocK 
Crystal, Quartz, Flint, Sand, and Sandstone. 

It exists in the stems of some plants, to which it seems 
to furnish the principal support. 

It is found most abundant in the straw of wheat, rye, 
oats, and barley, and in the stalk of Indian corn. For 
these purposes it is derived directly from the soil. 

In the arts it is used in the manufacture of glass, por- 
celain, and the various kinds of stone and earthen- 
wares. 

CHLORINE 
Is a heavy gas, of a greenish yellow color, and has a 
strong, suftbcating odor. 

A taper will continue to burn freely in it, but with a 
dim, smoky flame. 

Where does magnesia exist in nature? In what forms is it 
found in shops? 

What is epsom salts? How is silex formed? By what differ- 
ent names commonly known? 

In what part of plants found? For what pm-pose used in man- 
ufactures? Describe chlorine. What effect on a burning taper? 



28 



AGRICULTURAL CHEMISTRY. 



It is extremely irritating to tlie respiratory passages, 
when breathed even in the smallest quantities. It forms 
a large proportion of common salt, (Chloride of Sodium,) 
and an equal proportion of sal ammoniac, (Chloride of 
Ammonia.) The proportion of chlorine in each of these 
salts is sixty to every hundred pounds. 

Chlorine gas is easily prepared by adding chlorohydric 
acid to the oxide of manganese in a retort, or gas bottle, 
and applying a gentle heat. 

It may be collected 
in small quantities for 
immediate use, in a tall 
jar, by displacement; 
for its specific gravity 
is nearly two and a 
half times greater than 
that of the atmosphere. 
Fig. 1. When gathered over 

a pneumatic trough, like other gases, hot water, or a strong 
solution of common salt must be used, else much of the 
gas will be absorbed. Pure cold water will retain twice 
its bulk of chlorine, and this is a convenient method for 
retaining the gas for some purposes. 

This gas, as well as those compounds which produce it 
abundantly and economically, 4s used in the art of bleach- 




What eflPect on air passages? It forms a large propoi'tion of 
what ? 

How is chlorine prepared? In what, way is it collected? Why 
can it be gathered by displacement? 

Why necessary lo use warr 
ia it. used ? 



•m water or brine? In what art 



MATERIALS COMPOSING EARTHS. 



29 



PHOSPHORIC ACID 
Is a solid white substance, which, is seen, like white smoke, 
floating in the atmosphere after the burning of a common 
friction match. It is there formed by the oxygen of the 
atmosphere uniting with the phosphorus, which is combined 
with sulphur in the manufacture of matches. It exists in 
the bones of animals in very large proportion, in combination 
with lime, where it takes the name of phosphate of lime. 

Phosphoric acid is a very acid or sour substance, and, 
like chlorine, is extremely irritating to the respiratory 
passages. It is very readily ab- 
sorbed by water, and this union 
is attended with so much heat 
as to produce a hissing sound. 

This compound may be ex- 
hibited by burning a piece of 
l^hosphorus under a bell glass, ^^^. 
when the acid will fill the glass, ^ 
and descend as a fine light sub- ^^ 
stance, resembling snow. Fig. 2. 

SULPHURIC ACID, 
Or Oil of Vitriol, is an acid liquid of great specific gravity. 

It appears like an oil when poured from a vessel, and this, 
together with its intense acid properties, gives it this name. 

When pure, it rapidly destroys animal and vegetable 
substances, and chars wood when in contact with it. 




Describe Phosphoric acid. How is it formed ? Where does it 
naturally exist? What are its properties? How may its forma- 
tion be exhibited ? 

What is sulphuric acid? What is its appearance? What its 
effect on organic matter? 



30 AGRICULTURAL CHEMISTRY. 

Altliougli naturally transparent, it is rarely seen in this 
condition, as the least contact with an organic substance 
changes it to a dark color. 

It forms, when combined with various alkaline sub- 
stances, a class of compounds, which are called sulphates. 
The principal of these are Sulphate of Soda, (Grlauber 
Salts,) Sulphate of Magnesia, (Epsom Salts,) Sulphate 
OF Alumina and Potassa, (Alum,) and Sulphate of 
Lime, (G-ypsum.) These compounds are called salts. 

Although sulphuric acid is itself a very acrid substance, 
most of those salts which it contributes to form possess 
no such properties. 

Sulphuric acid is prepared by subjecting to a high tem- 
perature those substances with which it is found naturally 
combined, when it distills over as an oily liquid. 

The principal source of its preparation by this process 
is the sulphate of iron, commonly known as green vitriol. 

OXIDE OF IKON 
Is commonly known as iron rust. It is constantly form- 
ing by the union of oxygen of the atmosphere with iron, 
which may be exposed to it in moist situations. 

The surface of smooth or polished iron will thus be- 
come rusted, and that rust is an oxide of this metal. 

When a thin strip of iron is ignited, and then plunged 
into a jar which contains oxygen gas, the metal burns, 

Why is it usually of a dark color? What does it form by union 
with an alkali? What are the principal of these compounds? 

As a class, what are these compounds called? Do these salts 
possess any of the original px'operties of the acid ? 

How is sulphuric acid prepared? What is its principal source? 
How is oxide of iron constantly forming? How is it quickly 
formed? 



MATEEIALS COMPOSING EARTHS. 31 

and in this process throws off many sparks, which are 
found to be an oxide of iron. This does not differ from 
that which is formed by the slow process of rusting. 

The union of any metal with oxygen produces a sub- 
stance which is called an oxide, and the process by which 
the change is effected is called oxidation. 

OXIDE OF MANGANESE 

Is a black mineral, and when finely pulverized, is not 
readily distinguished, as commonly observed, from graphite. 

It exists in considerable quantities in but few localities, 
but is found in smaller quantities widely distributed. 

It is found in considerable quantities in Bennington 
and Pittsford, Vermont; and in Kent, Connecticut. 

It forms a small part of the ash of some plants, and is 
extensively distributed, but in very small quantities, in soil. 

Aluminum and Fluorine should be described in con- 
nection with this group, although they are not known to 
constitute any portion of organic substances. 

ALUMINUM, 
When united with oxygen, produces alumina. It is 
nearly pure in the gems called ruby and sapphire. 

In more impure conditions, or when combined with 
silica, it yields the common clays. 

Does oxide of iron prepared by burning iron in oxygen, differ 
from that formed by rusting in the atmosphere? 

What is the union of any metal with oxygen called ? What is 
the process called? What is oxide of manganese? Where found? 

Are aluminum and fluorine known to form any portion of or- 
ganic substances? 

What does aluminum form with oxygen ? What gems does it 
form? What does it form with silica? 



32 AGRICULTURAL CHEMISTRY. 

The presence of alumina imparts to clays those prop- 
erties which fit them for the purposes of the potter, the 
brickmaker, the manufacturer of PORCELAIN, and of the 
various kinds of earthenware. 

FLUOEINE 
Is found in combination with lime, as the fluoride 

OF CALCIUM, or FLOUR SPAR. 

It also occurs in the Topaz, and in some other min- 
erals. It forms a small portion of the enamel of teeth, 
and of the hardest portion of the bones of animals. 

The general properties of fluorine are not well under- 
stood, and it is known by its compounds only. 

Fluorine combines with Hydrogen, forming hydro- 
fluoric ACID, and this compound is remarkable as pos- 
sessing the power of corroding glass. The process of 
ETCHING upon glass was known, however, long before 
fluorine was suspected to exist. 



CHAPTER V. 

ORGANIC ELEMENTS. 



Those substances or elements which enter into the for- 
mation of organic structures are few in number, but are 
found in a great variety of forms and proportions. 

What properties does it impart to clay ? la what combina- 
tion is fluorine principally found? Where found in animal 
bodies? 

Are its properties well understood? What does it form with 
hydrogen? For what used in tlie arts? 



OKGANIC ELEMENTS. 33 

These are four, viz., Carbon, Nitrogen, Oxygen, and 
Hydrogen. The last three of these are gases, while the 
first always exists in a solid form. 

CAKBON 

Is found in several forms and conditions, which are quite 
diverse in character and appearance. These are the Dia- 
mond, Charcoal, Anthracite, and Bituminous Coal, 
Graphite, Coke, and Lamp-black. 

The DIAMOND is the hardest known substance. It is 
not acted upon by acids, or worn by friction, even when 
in contact with the hardest substances. It is, however, 
more readily injured by heat than many substances which 
are less hard ; for when heated to the temperature required 
for melting silver, it loses its value as a gem by becoming 
partially charred. 

The diamond is the most costly of gems. The cele- 
brated India diamond, the Koh-i-noor, now the prop- 
erty of the British crown, has been valued at ten millions 
of dollars. 

Charcoal is produced by the imperfect burning of 
wood, bones, and flesh. 

That the burning may be rendered imperfect the ma- 
terial from which it is produced must be nearly covered 
with earth, or some other substance, that will nearly ex- 
clude the oxygen of the atmosphere. Although it appears 

What are the organic elements? In what form do oxygen, 
hydrogen, and nitrogen exist? In what form carbon? 

What is the hardest known substance? Is it acted upon by 
acids or friction? What is the effect of heat upon it? 

How is charcoal produced? How is the burning rendered im- 
perfect? What are its qualities? 



34 AGRICULTURAL CHEMISTRY. 

soft, and may be easily broken, its fine particles are so 
bard as to scratch tbe hardest glass. 

Anthracite and Bituminous Coal are found imbedded 
in the earth, where they are often interposed among 
rocks. 

The principal difference between them consists in the 
absence of bitumen in the anthracite, which burns with a 
pure flame, but is useless in the manufacture of coal gas. 

GrRAPHiTE, also Called Plumbago and Black-lead, is 
used in the manufacture of lead-pencils, and to prevent 
the effects of friction in machinery. As it resists a high, 
degree of heat, it is employed in the manufacture of cru- 
cibles. 

Coke is produced by subjecting bituminous coal to a 
high temperature, so as to expel its bitumen, as in the 
manufacture of coal gas. 

Lamp-black is produced by the imperfect burning of 
bituminous substances, as the oil of pine and resin, on 
which it rises in the form of a dense black smoke, and is 
deposited in chambers prepared for its reception. 

KITEOGEN 
Is a gas which exists in the atmosphere, and in combi- 
nation with many substances which are used as food. 

The other element of the atmosphere, which is oxygen, 
may be separated from it by placing a piece of phosphorus 
in a tube with a bulb, or a bolt-head, over water. A por- 

Where are anthracite and bituminous coal found? Uovr do 
they differ? 

What is graphite? What are its uses? What is colie? How 
is lamp-black produced ? 

Where does nitrogen exist? What other element in the atmos- 
phere? How are these elements separated? 



OEGANIC ELEMENTS. 



35 




Fia:. 3. 



tion of the phosphorus will be slowly con- 
sumed, for it unites with the oxygen of the 
contained air. 

Both the phosphorus and oxygen are engaged 
in the process of slow combustion, and the water 
will rise and fill about one-fifth of the tube. 

That portion of the atmosphere which remains 
in the tube will prove to be nitrogen gas. This 
experiment proves that four-fifths of the atmos- 
phere is nitrogen, and the remaining fifth oxygen. 

If it is desired to test the gas which remains 
in the tube, or bell-glass, it is necessary to 
place the bolt-head and the vessel which contains the 
water (see Fig. 3) in a water trough, in order to trans- 
fer the gas to another vessel, which must be at least one- 
fifth smaller in order to contain nothing but the nitrosren. 

Nitrogen may also be pro- 
duced by burning phosphorus 
under a bell-glass, over water 
or mercury ; when the oxygen 
of the contained atmosphere will 
be burned out. or unite with the 
phosphorus, by which process 
phosphoric acid is formed. 

After the fumes have been 

absorbed, if over water, or have Fig. 4. 

fallen down in white flakes upon the fluid metal, if over 
mercury, the contents of the bell-glass will be found to 
be nitrogen gas. 

What change in the oxygen and phosphorus by this process? 
What effect on the water in the tube? 

What gas remains in the tube? How else may nitrogen be 
produced ? 





36 AGKICULTURAL CHEMISTRY. 

When free from oxygen this gas will not sus- 
tain the life of animals, or support the flame 
of a candle. 

To prove that it will not support flame, a 
lighted candle, or taper, may be lowered into 
a jar filled with the gas, which has been pre- 
pared by either process, when it will be extin- 
Fig. 5. guished. 

OXYGEN. 

The importance of OXYGEN will be inferred, when we 
learn that it forms one-fifth of the atmosphere, one-ninth 
of water, and not less than one-third of the whole mass 
of the crust of the earth. 

Oxygen, being the most extensively difi'used element 
in nature, is found in combination with all the elements, 
except fluorine. 

It is that portion of the atmosphere which is the chief 
agent in supporting animal life, and in the various pro- 
cesses of combustion. 

Its specific gravity is greater than that of the atmos- 
phere, the weight of which is intermediate between this 
substance and nitrogen. The particles of oxygen and 
nitrogen which compose the atmosphere are not chemi- 
cally combined so as to produce a third substance, as is 

What are the properties of nitrogen? How prove that it will 
not support flame ? 

How much each of atmosphere, water, and the earth, does 
oxygen form ? 

With what elements does it combine? With which does it not 
combine? 

What is its principal use in the atmosphere? Is it chemically 
combined with nitrogen ? 



OEGAXIC ELEMENTS. 37 

true in the union of hydrogen and oxygen to form water 
but float in rehxtion with each other, neither of them 
losing their individual character. 




Fig. 6. 

This element may be produced from several substances 
with which it has combined, and formed a solid. The 
separation of oxygen may be effected by the application 
of heat, varying in intensity according to the substance 
employed. The most convenient method for its prepara- 
tion is by mixing chlorate of potash with a small quan- 
tity of the oxide of manganese in a retort, and applying 
heat with a spirit-lamp. 

The gas may be collected in a bell-glass over a pneu- 
matic-trough. The lamp should be slowly removed from 
the retort, in order to secure it against breaking. 

Oxygen may also be produced in the same manner 
from the Peroxide of Mercury, (Red Precipitate,) but 
more heat is required than when chlorate of potash and ' 
manganese, or chlorate of potash alone is used. 

By what means is oxygen prepared ? What are the most con- 
venient substances used in its production? 

How is this gas collected ? What other convenient method for 
its production? 



38 



AGIIICULTUEAL CHEMISTKY. 



This is one of the most interesting- experiments which 
can be introduced, for both elements of which the sub- 
stance used is composed, may be collected and weighed; 
and the fact is thus demonstrated, that no part of the 
materials is lost, although their appearance and properties 
are entirely changed. 




Fig. 7 

By this method the mercury, (quicksilver,) which is 
the only metal that retains a fluid form at ordinary tem- 
peratures, may be collected in a globe, which takes the 
place of Wolfs bottle. 

If two hundred grains of peroxide of mercury are used, 
one hundred and eighty-five grains of mercury will remain 
in the globe, and fifteen grains of oxygen will be gathered 
in the bell-glass over the pneumatic trough. The fifteen 
grains of oxygen will be found to occupy forty-four cubic 
inches of space. 

Why is its production by the use of oxide of mercury pecu- 
liarly interesting? 

If two hundred grains of oxide of mercury are used, how many 
grains of mercury are produced, and where found ? 

How many grains of oxygen? How much space will the oxygen 
occupy ? 



OEGANIC ELEMENTS. 



39 




Fi2. 



That oxygen, tliough not itself combustible, is one of 
the supporters of combustion, may be proved by lower- 
ing a taper, or bit of charcoal, with the smallest spark, 
into a jar of the gas, when it will burn with a 
brilliant flame, and be consumed with great 
rapidity; but whenever removed from the jar, 
the combustion ceases ; but is renewed when 
the charcoal is returned, provided it retains 
the smallest ignited point. This may be 
rapidly repeated many times in the same jar 
of oxygen. (Fig. 8.) 

A w\atch-spring, or fine wire, with a glowing 
point, will kindle and burn very rapidly, 
throwing off brilliant sparks, when plunged 
into this gas. (Fig. 9.) 

HYDEOGEN. 

Hydrogen forms the principal part of coal ^" ' "*' 
gas, which contains, also, a minute quantity '^'^S- 9- 
of carbon, and other impurities. 

Hydrogen gas is produced by pouring over some strips 
of zinc, or, what is better, some finely granulated zinc, 
or iron filings, some sulphuric acid, diluted with five parts 
of water. 

The most convenient method for its prepa^-ation is, by 
the use of a common gas bottle, with a wide mouth, fitted 
with a cork, which is pierced by a tube, funnel-shaped at 
the top, and leading to the bottom of the bottle, in order 




What are the properties of oxygen? What are its relations 
to combustion? 

What does hydrogen gas form the principal part of? How is 
it produced ? What apparatus is used ? 



40 



AGRICULTURAL t'HExMIBTRY. 



to facilitate the introduction of the liquid. Another tuhe, 
which must barely pierce the cork, should extend under 
the bell glass, over the pneumatic trough. (Fig. 10.) 




Fig. 10. 

No heat is rec^uired in the preparation of this gas, but 
much will be evolved, if the acid is occasionally added 
to the mixture in the gas bottle. 

Great care must be observed to avoid the mixture 
of atmosphere with this gas, as this combination, when 
inflamed, will produce a violent explosion. 

When pure, hydrogen will take fire on the application of 
a lighted taper, and burn with a feeble flame and the most 
intense heat, especially when the jet is joined by one 
of oxygen. This union of the gases in the jet forms 
what is called the oxy-hydrogen blow-pipe. Hydrogen, 
though combustible, is not a supporter of combustion. 

Any substance which is lighter than the atmosphere 
will rapidly escape from a vessel, unless it is inverted. 



Is any heat required in its preparation ? Why should we avoid 
a mixture of atmosphere with it when burned? 

What are its properties? What elfect if united with oxygen 
when burned ? 



OKGANIC ELEMENTS. 41 

Those substances, only, wliich are heavier than the atmos- 
phere, are retained when the vessel stands upright. For 
this reason oxygen will remain for a short time in an 
upright jar, while nitrogen and hydrogen will readily 
escape. 

Hydrogen can be tested with regard to its property of 
not supporting combustion, while it burns itself, only, when 
the mouth of the vessel is turned downward. 

If a burning taper is carried upward into a bell-glass 
filled with hydrogen, it will be extinguished, after first 
setting fire to the lower surface of the gas. The gas will, 
however, continue to burn, until, in a few seconds, all is 
consumed. 

Hydrogen may be prepared in a bottle with a pipe- 
stem or glass tube piercing the cork. 

The gas will take fire by the application of flame, 
as it escapes from the orifice, and continue to burn 
with a feeble flame. This has been called the 
" Philosopher's lamp." The cork should not be 
introduced for a few moments after the mixture, in 
order that the air which the bottle contains may be 
expelled, or an explosion may take place. (Fig. 11.) Fig. ll. 

The most convenient plan for exhibiting the burning 
properties of this gas is by placing the materials for gen- 
erating it in the bottom of a tall glass, and covering 
for a few moments, in order that a small quantity may 
accumulate. 

Does hydrogen support combustion? How proved that it does 
not? 

Describe the philosopher's lamp. What precautions are neces- 
sary in its use? 

What is the most convenient plan for exhibiting the burning 
properties of hvdrogen ? 
4 



42 



AG-EICULTUEAL CHEMISTRY. 




Fig. 12. 



On removing tlie cover, and quickly 
applying a taper, a slight explosion will 
take place. (Fig. 12.) 

Hydrogen gas is the lightest of all 
known substances, being fifteen times 
lighter than the atmosphere. This prop- 
erty renders it an appropriate material 
for inflating balloons.* 



CHAPTER VI. 



COMPOUNDS PRODUCED BY DECOMPOSITION OF ORGANIC 
MATTER. 

The forms which organic substances assume when de- 
composed, are principally three. 

These forms are water, carbonic acid, and ammo- 
nia; and they are compounds of the four organic ele- 
ments, in various forms and proportions. 



How much does 100 cubic inches of hydrogen weigh? Of ni- 
trogen — atmosphere — oxygen — carbonic acid, and chlorine? What 
use does its peculiar lightness fit it for? 

How many forms do organic substances assume when decom- 
posed ? Of what elements are they composed ? 

*NoTB. — This table indicates the comparative weight of several com- 
mon substances. Fractions are omitted : 

100 cubic inches of hydrogen weigh 2 grains, 
nitrogen " 30 " 
atmosphere " 31 " 
oxygen " 34 " 

carbonic acid " 47 " 
chlorine " 76 " 



OEGANIC COMPOUNDS. 43 

Water is composed of oxygen and hydrogen, chem- 
ically combined, in the proportion of eight parts of the 
former to one of the latter. 

This compound is one of the sources of the elements 
of which it is composed, as furnished to vegetable tissues. 
Its principal use is a physical one, for by its agency, the 
nutritive materials appropriated by plants and animals, are 
conveyed through their vessels. 

Carbonic acid is a gas, but it exists as a solid when 
combined with the alkalies and ALKALmE earths. It 
combines with lime, potash, soda, magnesia, and some 
other substances, and forms a class of compounds which 
are called carbonates. 

Many specimens of lime rock contain in each hundred 
pounds, forty-four pounds of carbonic acid and fifty-six 
pounds of lime. 

Carbonic acid gas is abundantly produced by the com- 
bustion of wood, and other substances which contain 
carbon. 

It is also furnished to the atmosphere, in very large 
quantities, by the breathing of animals, by the various 
processes of fermentation, and by the decay of animal and 
vegetable matter. 

Considerable quantities may also be separated from 
marble, chalk, and lime rock, by the application of heat, 
as in a lime-kiln. 

Of what is water composed? What are its uses? Where does 
carbonic acid exist as a solid? 

What class of compounds does it form with alkalies ? How 
much carbonic acid in each 100 pounds of lime rock ? 

How is it abundantly produced? How is carbonic acid natur- 
ally furnished to the atmosphere? How separated from marble, 
chalk and lirae rock ? 



44 



AGRICULTURAL CHEMISTRY. 



This gas exists, free, in nature, in all well and spring 
water, from which it is expelled by boiling. It is so 
abundant in many springs as to escape in bubbles from 
the surface of the water, as those of Saratoga, in the State 
of New York, of Baden Baden and Carlsbad, in Germany, 
and of Pyrmont, in England. 

Carbonic acid is heavier than the atmosphere in the pro- 
portion of forty-seven of the former to thirty-one of the 
latter, and, like chlorine, may be gathered by displacement 
of air from the vessel. 

It sometimes accumulates in old wells, which are not 
used, and in deep caverns, where the air is seldom agitated, 
where it has long been known as Choke Damp, from its 
fatal effects when incautiously breathed. 




Fiff. 13. 



This gas may be conveniently prepared by pouring some 
diluted CHLOROHYDRic ACID upon CHALK, or any of the 
carbonates, by which process the carbonic acid is sep- 
arated. 



Where does carbonic field exist free in nature ? 
In what proportion is it heavier than the atmosphere? Where 
does it sometimes accumulate? How can it be prepared? 



ORGANIC COMPOUNDS. 



45 




Fit?. ]-i. 



This gas does not support animal life or 
combustion. That it does not support com- 
bustion may be demonstrated by lowering a taper 
into a jar filled with the gas, when it will be 
extinguished. 

That it is heavier than the atmosphere may be 
proved by pouring it from a jar, into one which 
has a burning taper, (figs. 14 and 15,) at the 
bottom, when the light is soon extinguished. 

Carbonic acid is the princi- 
pal source of food for plants, as 
most of the carbon which enters 
into their formation is derived 
from it. 

Ammonia is a gaseous com- 
pound, and is naturally pro- 
duced by the decomposition of 
such animal and vegetable sub- , 
stances as contain nitrogen. It 
is composed of hydrogen and 
nitrogen, and its composition is 
expressed in symbols, thus : Hg N 

It is a volatile alkali, 
those which are fixed or solid. 

It may be produced by heating in a flask equal quan- 
tities of slaked lime and sal ammoniac. 

As it is lighter than the atmosphere, it may be col- 




Fig. 15. 



which term distinguishes it from 



What are its pi-operties? How proved that it is heavier than 
the atmosphere? 

What does it contribute to growth of plants? What is am- 
monia? How naturally produced? Of what elements composed? 

What kind of an alkali is it? How may it be artificially pro- 
duced? 



46 



AGRICULTURAL CHEMISTRY. 




lected, by the method of displacement of air, the 
vessel in which it is received being inverted over 
the tube from which the gas escapes. (Fig. 16.) 

Ammonia is remarkable for its strong affinity 
for water, and is consequently readily absorbed 
by it. This solution is called aqua ammonia, 
and is the form in which it is most commonly 
sold and used. 

By union with acids, like other alkalies, it forms 
salts, and thus loses the pungent odor peculiar to 
Fig. 16. this gas. 

When ammonia is combined with aromatics, it forms 
the smelling salts of the shops. 

Ammonia is one of the most active elements of farm- 
yard manure ; but, without great care, large quantities of 
this valuable fertilizer are lost from the farm-yard, and 
carried off in the atmosphere. 

That ammonia has a strong affinity for acids 
may be shown by bringing a glass rod, which 
has been dipped in chlorohydric acid, over a 
vessel containing ammonia, when a dense white 
cloud is seen to rise, which is chloride of am- 
monium. (See Fig. 17.) 




Fig. 1^ 



Is it heavier or lighter than the atmosphere? How proved? 

For what is ammonia remarkable? In what form is it most 
commonly used ? 

Does it form salts with acids? Does it thus lose its pungent 
odor? 

Is it an active element of manure? Why is it readily lost from 
manure ? How proved that it has a strong affinity for acids ? 



MATERIALS COMPOSING PLANTS. 47 



CHAPTER VII. 

MATERIALS OF WHICH PLANTS ARE COMPOSED. 

All plants, among wliich are numbered the wliole 
range of vegetables, trees, and grains, are composed 
of two kinds of materials, or parts, which are distin- 
guished by the terms ORGANIC and INORGANIC. 

The ORGANIC portion is readily burned away in the 
fire; and this quality distinguishes it from the inorganic 
portion. 

The INORGANIC part is not consumed by the action of 
fire, but remains after the organic part is burned away, 
and is known as their ashes. 

The organic portion of all plants is much greater than 
the inorganic part, but the proportion varies very greatly 
in the dilEFerent kinds of plants, or woods. This portion 
varies from ninety to ninety-nine parts in a hundred, in 
the diiferent grains and woods. 

The elements which compose the organic part are very 
few in number, but they exist in a considerable variety 
of forms. These elements, being four in number, are 
Carbon, Nitrogen, or Azote, Hydrogen, and Oxygen, 
(See Organic Elements.) 

Of what two classes of materials are plants composed ? How 
is the organic portion separated? Which part is the greatest? 

How great is the organic portion ? What elements compose the 
organic part of plants? 



48 AGRICULTURAL CHEMISTRY. 



CHAPTER VIII. 

THE INORGANIC COMPOUNDS IN PLANTS. 

Those inorganic substances which exist in the largest 
quantity in plants are as follows, and are placed in the 
order in which they exist in most plants in the largest 
proportion. They are Potash, Soda, Lime, Magnesia, 
Phosphoric acid, Sulphuric acid, and Silica, Oxide 
op Iron and Oxide of Manganese exist in plants, but 
in much smaller proportion. 

The four first elements, or the combinations which they 
form, being driven off, or consumed by heat, the inor- 
ganic portion remains, but may afterward, mostly, be dis- 
solved in water, and then gathered in troughs, while in 
solution. 

/ The most common and abundant of these substances is 
Potash, which is procured by the process of leaching of 
common wood ashes, and then evaporating the solution 
by boiling. Large quantities of this substance are pro- 
duced in those localities which abound in forests, and 
sold for the purpose of manufacture into soap and glass. 
This article has been the source of considerable revenue 
from foreign countries. 

Soda is much more abundant in the ashes of marine 

What are the principal inoi'ganic substances? In what con- 
dition may the inorganic substances be gathered? 

Of these which is the most abundant? How is it procured? 
What localities produce most potash? For what purpose used in 
the manufactures? 



mORGANIC COMPOUNDS IN PLANTS. 49 

plants, (kelp,) but exists, tliougli in much smaller pro- 
portion, in the ashes of common plants and woods. 

Lime forms but a small portion of the structure of 
plants. It constitutes a larger portion of the ashes of oats 
than of any other common grain. In some instances the 
proportion is as much as ten per cent. 

Magnesia exists in much larger proportion in the ashes 
of wheat than in lime, for the proportion is nearly ten per 
cent, in wheat, while that of lime is less than two per cent. 

Phosphoric acid is found in very large proportion in 
the ashes of some grains. In wheat, oats, barley, and rye, 
it forms between forty and fifty per cent. It exists mostly 
in conjunction with lime, forming the phosphate of that 
substance. 

Sulphuric acid constitutes but a small proportion of 
the inorganic part of common plants ; for it forms less 
than one per cent, in most of them. 

Silica, although it exists in vast quantities as a con- 
stituent of the earth, forms from less than one to more 
than twenty per cent, of the ashes of common grains. It 
is found in the largest proportion in that of barley. 

Oxide of Iron exists in the largest proportion in oats, 

In what plants is soda most abundant? In what proportion 
does it exist in common plants? In what plant is lime most 
abundant? 

In what plant is magnesia most abundant? In what plants 
is phosphoric acid most abundant? In which does it form more 
than 40 per cent, of the ash? 

With what is it mostly in conjunction ? Does sulphuric acid 
constitute much of the inorganic part of plants ? 

What is the range of the proportion of silica in the ashes of 
the common grains? In the ashes of what grain is it most 
abundant? 
5 



50 AGRICULTUEAL CJIEMISTRV. 

in which grain it forms about five per cent, of the ashes. 
It forms a little more than one per cent, of the ashes of 
common grains. 

Oxide of Manganese may be discovered in the ashes 
of grains, but in most of them it forms but a very small 
part, often much less than one per cent. 

It has already been ascertained that the ashes of all 
plants, of whatever kind, are composed of but nine com- 
pound substances, although minute traces of a small ad- 
ditional nu7nber may sometimes be discovered in them, 
only by the most delicate tests. 

These substances are destined to perform a variety of 
offices in the economy of common vegetables. They fur- 
nish a means of support to the stem of some, while in 
others they exist mostly in the fruit or berry. 



CHAPTER IX. 

ORGANIC C03IP0UNDS IN PLANTS. 

The common organic forms which exist in i^lants are 
chiefly Woody Fiber, Starch, and Gluten. Sugar, 
Oil, and Gum, exist as a constituent peculiar to some 
plants, and are much like starch in their characteristic 
chemical elements. 

In the ashes of what grain is the oxide of iron most abundant? 
How much in the ashes of common grains? 

Does the oxide of manganese constitute much of the ashes of com- 
mon grain? 

What number of compound substances in the ashes of all plants? 
What are the oflfices of these substances in plants? What are the 
common organic forms in plants ? 



ORGANIC COMPOlfNDS IN PLANTS. 51 

AVooDY FIBER is that material which forms the largest 
portion of all kinds of wood, of the stems of common 
plants, as hay, grains, and grasses, of chaff, and husks, 
of the shells of nuts, the fiber of cotton, flax, and hemp. 

Starch exists in great abundance in the roots of some 
plants. It forms nearly the entire substance of some 
bulbous roots, as the potato and arrow-root, and exists 
in large proportion in wheat and rye flour, in oat and 
corn-meal, and in the flour of all grains which are culti- 
vated as food. It is also found in the stems of some 
plants or trees, and there is called pith. 

Gluten exists along witlv starch in the flour of mo'St 
kinds of grains. 

It may be separated from starch in flour with which it 
is associated, by first wetting the flour, and making it into 
dough, and afterward washing with water, which should 
be done over a sieve or thin cloth. This will allow the 
starch to pass through, aud the gluten will be left as a 
soft mass, for it is not dissolved by water. 

The starch is not dissolved by this process, but its par- 
ticles (granules) are so small, and so readily separated 
by water, as to pass through the small openings in the 
cloth. 

Of these substances, woody fiber is most abundant in 
the stems of plants, while starch and gluten are mostly 
found in their seeds. 

What is woody fiber ? Where is starch found ? With what is 
gluten associated ? How may starch and gluten be separated ? 

How is the starch disposed of? Where is woody fiber abund- 
ant? Where is starch and gluten found? 



52 AGKICULTUEAL CHEMISTliY. 



CHAPTEE X. 

SUBSTANCES FORMED MOSTLY OF CARBON. 

Five common substances which are produced by plants, 
consist principally of carbon. These, as before mentioned, 
are woody fiber, starch, gum, sugar, and oil. 

The last four serve as food for men and animals, while 
the first is mostly useful as fuel, and as material for ma- 
chinery, architecture, and the manufacture of cloth. 

Carbon is the princij^al element in these five substances, 
and exists here in combination with other elements, 
but in quite dilferent proportions. These other elements 
are oxygen and hydrogen, which are here combined in 
the form of water. 

Every nine pounds of water are composed of eight pounds 
of oxygen, and one pound of hydrogen. 

Every thirty-six pounds of woody fiber are composed of 
eighteen pounds of carbon, and eighteen pounds of water. 

Every forty and a half pounds of starch or- gum are 
composed of twenty-two and a half pounds of water, and 
eighteen pounds of carbon. 

Eighty-five and a half pounds of loaf-sugar are com- 

What five common substances consist principally of carbon ? 
What purposes do the last four serve? What the first? 

With what element is carbon here associated? In what form 
here do the other two elements exist? 

What are the proportion of these elements in water? In thirty- 
six pounds of woody fiber? In forty and a half of starch or 
gum? 



THE ATMOSPHERE. 53 

posed of forty-nine and a half pounds of water, and thirty- 
six pounds of carbon. 

Starch, then, is composed of the same three elements 
which form charcoal and water. Woody fiber and gum are 
composed of the same elements, but in different propor- 
tions, although their appearance and uses are so unlike. 

Much of the material out of which these substances 
are formed, is derived from the atmosphere in the form 
of carbonic acid, this compound being always present in 
the form of a gas. 



CHAPTER XI. 

THE ATMOSPHERE. 



Atmospheric air is composed of oxygen and nitrogen 
gases, in the proportion of about one part of oxygen to 
four of nitrogen. 

Although oxygen forms but one-fifth of the atmos- 
phere, it is the active agent in the combustion of wood 
and coal, and in the decomposition of plants and animals. 

Experiments prove that if the atmosphere was com- 
posed of pure oxygen, every organic substance would 
speedily be burned up, and all metals would be rapidly 
changed by the process of oxidation. 



In eighty-five and a half of loaf-sugar? What other substances 
are composed of the same elements as starch? 

What is the source of much of the material out of which these 
are built up? In what form? 

Of what is the atmosphere composed? Which is the active 
agent in combustion and decomposition? W^hat if the atmosphere 
was composed of pure oxygen ? 



54 AGRICULTURAL CHEMISTRY. 

Nitrogen seems to be siijDplied to the atmospliere in 
order to dilute its oxygen, and thus reduce the intensity 
of its effects. 

The atmosphere contains other substances, but in small 
quantities. These are commonly called impurities, but 
they are such only with regard to animals, for they are 
found to promote the growth, and contribute to the health 
of vegetables. 

Such substances, in addition to carbonic acid, are water 
and ammonia, (see p. 57,) and are mostly furnished to the 
atmosphere by the decay of vegetables and animals. 
However, some are furnished from other sources. 

The proportion of carbonic acid in the atmosphere is 
about one j^art in twenty-five hundred, and although a 
large portion (at least one-half) of all vegetable substances 
is derived from this source, its proportion in the atmos- 
phere is always nearly the same. 

We thus learn that carbonic acid is constantly produced, 
and in large quantities, and is as constantly used by plants 
in the building up of their structure. 

Carbonic acid being formed of carbon and oxygen, is 
composed for every twenty-two pounds of the compound, 
of sixteen pounds of oxygen and six pounds of carbon. 
Its source, in addition to the breathing of animals, and 
the decay of animal and vegetable substances, is by the 
various processes of fermentation, as of beer, wine, and 

CIDER. 



What seems to be the use of nitrogen ? What other substances 
called impurities in the atmosphere ? How are these principally 
furnished ? 

What is the proportion of carbonic acid in the atmosphere ? 
Why does the quantity not accumulate in the atmosphere? What 
additional sources of carbonic acid ? 



FORMS OF FOOD FOR FLANTS. 55 



CHAPTER XII. 

FORMS IN WHICH NUTRIMENT IS RECEIVED BY PLANTS. 

The materials out of wliicli plants are constructed 
are received by tliem, in tlie form, either of liquids or 
gases ; but every plant possesses within itself the power 
to change these substances, and to fit them for future 
use. 

Plants possess the power of receiving certain inor- 
ganic materials from the earth, and so changing their 
properties as to fit them for contributing to the support 
of other plants, and of animals. 

They receive carbonic acid gas from the atmosphere, 
through the agency of their leaves, for these are the respi- 
ratory organs of plants. 

It has been estimated that more than a hundred and 
seventy thousand small openings (stomata) exist upon the 
surface of a leaf of some plants, while others are supplied 
with a much smaller number. These openings are mostly 
found upon the under surface of the leaf. 

Leaves, then, perform important offices in the growth 
of plants, for they assist in the preparation of the sap, ;^n 



In what, forms are materials of which plants are constructed 
received by them? What an agency in the change of gases in 
plants? 

What changes do plants themselves effect in the materials 
which are destined for their support? 

Through what organs do they receive carbonic acid? What 
other office do leaves perform ':' 



56 AGRICULTUKAL CHEMISTRY. 

the evaporation of water, and in the separation of 
oxygen from the carbonic acid, which is returned 
again to the atmosphere. The carbon remains in 
order to contribute to the formation of the woody 
fiber, fruit, etc., and this is principally effected 
Fig. 18. under the influence of light. (Fig. 18.) 




CHAPTER XIII. 

SOURCES OF NITROGEN. 



Nitrogen is mostly furnished to plants by means of 
ammonia, and this element is fixed from ammonia by pro- 
cesses which to some extent correspond to the retention 
of carbon from carbonic acid. 

Ammonia is composed of hydrogen and nitrogen. (See 

p. 1.) 

Seventeen pounds of ammonia are composed of three 
pounds of hydrogen and fourteen pounds of nitrogen, and 
is written in symbols thus, N H3. 

The muscles of animals, and that portion of plants 
which is called gluten, as well as vegetable albumen, con- 
sists mostly of nitrogen, but in combination with other 
elements. 

What becomes of the carbon of the carbonic acid ? What of the 
oxygen ? 

By what means are plants furnished with nitrogen? Of what 
is ammonia composed? 

What number of atoms in each element in seventeen pounds 
of ammonia? 

What parts of animals and plants are composed mostly of 
nitrogen ? 



SOURCES OF NITR0GEJ7. 57 

When these substances are decomposed, they unite with 
hydrogen, and thus form ammonia, and the ammonia thus 
formed in turn is furnished as food for phmts. 

Carbonic acid, being hirgely formed by the decompo- 
sition of vegetables, ammonia, in like manner, is largely 
produced by the decomposition of animals ; but a certain 
portion of each is formed by the decomposition of both 
plants and animals. 

Ammonia, like carbonic acid, pervades the atmos- 
phere, but is imbibed by plants, mostly, if not entirely, by 
a different set of organs. It enters into the circulation, or 
sap of plants, through the fine spongy extremities of 
their roots, (spongioles,) and consequently must first be 
dissolved. 

Water has the power to absorb many times its bulk 
of ammonia, and ammonia, in turn, has a strong ten- 
dency to approach water, and to be absorbed by it. It is 
by this means that rain water, snow, and dew, are always 
charged with a certain quantity of this compound, which 
they impart to plants, to promote their growth. 

Water from wells, springs, and streams, does not con- 
tribute to the growth of plants to the same extent, unless 
it has previously been charged with ammonia. 

When decomposed, with what does it unite? "What does it thus 
form ? 

What compound is mostly formed by the decomposition of vege- 
tables? What of the decomposition of animals? 

By what organs is ammonia absorbed by plants? In -what con- 
dition? 

By what substance is much ammonia absorbed? What com- 
mon substances contain ammonia? 

Why does not well and spring water contribute as much as 
these to the growth of plants? 



58 AGEICULTURAL CHEMISTRY. 

The body of an animal, by its decomposition, produces 
both carbonic acid and ammonia, in addition to water. 
Carbonic acid is furnished by the decomposition of the 
fatty portion, and ammonia by the muscles of animals. 

A small quantity of ammonia, only, is furnished by the 
decomposition of vegetables, for but a limited portion of 
substances which contain nitrogen enter into their com- 
position. One of these substances (carbon) is mostly 
received through the leaves of plants, while the other 
(nitrogen) is imbibed by their roots. 

The substance which is derived from the atmosphere is 
received through the leaves of plants in the form of a 
gas, and the other, dissolved in water, is imbibed through 
their roots. 

Although the atmosphere is composed of nitrogen and 
oxygen, (see p. 53,) we have no evidence that either of these 
elements furnish any material which contributes to the 
structure of plants. 



CHAPTER Xiy. 

MATERIALS OF WHICH SOIL IS COMPOSED. 

Soils from which plant* ^row, like plants themselves, 
are composed of organic and inorganic materials. 



What substances are formed by the decomposition of animals? 
From what is carbonic acid furnished ? 

From what part is ammonia furnished? Why is so little am- 
monia furnished by the decomposition of vegetables? 

Does nitrogen of the atmosphere furnish material for the struc- 
ture of plants? -Of what materials are soils composed? 



MATERIALS FORMING SOILS. 59 

This fact is proved by the same method, or that of 
burning. 

Mineral, or inorganic matter, is not aifected by 
burning in such way as to diminish its weight or bulk, 
beyond what is lost by driving off the water which it may 
contain, when it escapes in the form of vapor. 

If a given quantity of soil is exposed to fire, or the 
action of heat, a portion is consumed, or driven off, in 
the same manner as the organic part of wood. The ashes 
which remains will be the exact proportion of the inor- 
ganic part of the soil. 

The organic portion of soil is derived from the roots, 
stems, and leaves of plants, from the excrement and 
remains of the various animals and insects. 

The organic part of the most fertile soil composes from 
one-tenth to one-twentieth of its weight. 

In PEATY SOILS, the organic portion is sometimes equal 
to three-fourths of its whole weight, but such soils are 
poorly adapted to the growth and support of common 
vegetables. 

Peaty soils are unproductive and they are so on account 
of their resistance to decomposition, for this is necessary 
in order that any soil may become food for plants. 

The proportion of organic matter in soils will be dimin- 
ished by the crops which are raised from them. Some 



How is this proved? How is the proportion of inorganic 
matter in soils determined? 

From whence is the organic portion of soils derived? What is 
the proportion of organic material in fertile soils? 

What is the proportion of oi'ganic materials in peaty soils? Are 
such adapted to the support of common vegetables? 

Why are peaty soils unproductive? How is the oi"ganic matter 
iu soils diminished? 



60 AGEICFLTUEAL CHEMISTRY. 

materials may be removed while others remain, and this 
will correspond in degree, with the nature of the crops which 
are raised. 

We learn with regard to the adaptation of a soil, for 
the raising of any given kind of grain, by first ascertaining 
what the materials are of which the grain is composed, 
and then the substances which exist in the soil. 

A soil may be quite well adapted to the raising of one 
kind of grain, and at the same time poorly adapted to 
produce another, while the proportion of organic elements 
may remain about the same, but may differ in kind. 

The farmer will learn with regard to the most profitable 
crop which he can raise from a given field by first ascer- 
taining the particular organic materials which exist in that 
field. 



CHAPTER XV. 

SOURCES OF THE INORGANIC PORTION OF SOIL, 

The inorganic portion of soil is derived from the 
crumbling down of the various kinds of solid rocks. 

This fact may be verified by observing the character 
of the earth which is found by the side of any given ledge 
of rocks. Such earth will be mostly composed, in its in- 
organic constituents, of the same materials as the rocky 
mass by the side of which it is found. 

Does each crop remove all materials alike? May a soil be 
well adapted to the raising of one grain and poorly adapted to 
another? 

How does the farmer learn to adapt his crop to a given field? 

From whence is the inorganic portion of soil derived? How 
may this be verified? 



I 



SOURCES OF INORGANIC MATERIALS. (Jl 

These changes in the condition of materials of which 
rocks are formed, are produced by a variety of agencies. 
The most common, and constantly acting agency in secur- 
ing such change, is the union of the original material of 
which the rock is formed with the oxygen of the atmos- 
phere. 

Those latitudes where the change of temperature in the 
different seasons is greatest, are best adapted to j)roduce 
these changes, even in the most solid rocks. 

The crumbling down of rocks is sometimes effected on 
an immense scale by the action of frost upon such masses 
as contain considerable water, for large fragments are often 
separated by the expansive force of water while freezing. 

Rocks are not only broken down by these means, but 
smaller fragments, and particles even, are thus separated, 
and crumble down to fine dust. These processes furnish 
a soil which is composed of matter similar in its chemical 
constituents to the rock itself. 

EOCKS WHICH FOKM SOILS. 

Those rocks which contribute mostly to the formation 
of soils are Sandstone, Limestone, and Slate. 

Sandstone, which is composed mostly of silica, is of 
different colors, and this variation in color is principally 
produced by the presence of a very small quantity of some 
one of the different forms of iron. The largest number 

By what agencies are changes eflFected in the matei'ials of which 
solid rocks are composed? What latitudes are best adapted to 
effect these changes? 

How does water contribute to eiFect these changes? What kind 
of soil do these processes furnish? 

What rocks contribute mostly to the formation of soils? Of what 
is sandstone composed? Of what colors is it found? 



02 AGRICULTURAL CHEMISTRY-. 

of sandstones are red, or white, but they are found of a 
great variety of hues, some of which are black, gray, and 
green. 

Limestone is found in great abundance and in many 
localities. The most common form is the gray lime-rock; 
but it is often combined with magnesia, when it takes the- 
name of magnesian lime-rock. 

The next most abundant form of carbonate of lime is 
CHALK, which exists in large masses on the coast of Eng- 
land, especially along the British Channel. 

Marble is the least abundant form of this kind of 
rock, but it exists in such masses, in a few localities, as to 
contribute to give character to soil. 

Marble is found of a great variety of cojors and tex- 
ture, from the pure white materials used for statuary, to 
those which are variegated, and of various hues, some of 
which are used for building purposes. 

Slate or Shale, is a source of clay soils. It is found 
in masses, arranged in thin layers, as those from which 
slates for the school-room, and slate roofing are made. 

Slate is not found in as great abundance as the quantity 
of clay found in soils would naturally lead us to expect. 

What is the most common form of limestone ? What is the next 
most abundant form of carbonate of lime? 

Does marble contribute to give character to soils ? What is the 
source of clay soils? 

In what form is slate found? Is it abundant? 



CLASSIFICATION OF SOIL. 



63 



CHAPTER XVI. 

CLASSIFICATION OF SOIL. 

Soils are named from the amount, or proportions, of 
the various substances which enter into their formation. 
If a soil consists principally of sand, it is called a sandy 

SOIL. 

If the largest portion is clay, it is called a clayey soil. 
When lime predominates, it is called a calcareous 

SOIL. 

Those substances may exist together, but in different 
proportions, in the same soil, in which case it usually 
receives a distinct name. 

A mixture of sand and clay, with a small portion of 
lime, is called a loaji. 

If it contain much lime, it is called a calcareous 

LOAM. 

If it is composed of clay, with much lime, it is called 

a CALCAREOUS CLAY. 

A certain proportion of these substances has given 
specific names to soils. 

Pure clay, which is commonly called pipe clay, is com- 
posed of about sixty parts of silica, and forty parts of 

From what are soils named? What is a sandy soil— a clay 
soil — a calcareous soil? 

What constitutes calcareous clay? What gives specific names 
to soils? 

What is pure clay commonly called? Of what is it com- 
posed ? 



64 AGRICULTUBAL CHEMISTRY. 

alumina, witli a small quantity of oxide of iron. This kind 
of clay contains no silicious sand whicli can be separated 
by washing with water. It forms but a small quantity of 
soil, and is found in comparatively few localities. 

Tile clay forms the strongest clay soils. It consists 
of pure clay, mixed with from five to fifteen per cent, of 
silicious sand, which can be separated from it by boiling, 
or washing. 

Clay loam contains from fifteen to thirty per cent, of 
fine sand, which can be separated by boiling. The differ- 
ent parts of this soil may be very easily separated, and is 
consequently more easily worked. Such soil is very prop- 
erly sought for in the selection of a farm. 

A LOAMY SOIL contains from thirty to sixty per cent, 
of sand, which is retained so loosely that it can be readily 
separated from it by washing. 

A SANDY LOAM leavcs from sixty to ninety per cent, of 
sand. 

A SANDY SOIL consists mostly of sand, and contains no 
more than ten per cent, of clay. 

In a MARLY SOIL the proportion of lime must be more 
than five per cent., but less than twenty per cent. 

Marls are called sandy, loamy, and clayey, in accord- 
ance with the proportions they may contain of these sub- 
stances, provided they be free from lime, or do not contain 
more than five per cent, of this material. 



Does this contribute to form much soil? Of what does tile clay 
consist? What does clay loam contain? 

Is clay loam a valuable soil? What does a loamy soil con- 
tain? A sandy loam? Sandy soil? A marly soil? 

What different names are given to marly soils? What is the 
source of these names? 



I 



MANURES. 65 

Soils are denominated calcareous when the proportion 
of lime exceeds twenty per cent., and thus by its quantity 
becomes an important constituent. 

There are also calcareous clays, calcareous loams, 
and calcareous sands, which take their names from the 
proportion of clay and sand which they may contain. 

Vegetable mold is sometimes a prominent charac 
teristic of a soil. 

In peaty soils, its proportion may be equal to sixty 
and sometimes as much as seventy-five per cent. 

Garden mold contains no more than five per cent, 
of organic matter. 



CHAPTER XVII. 

manures. 

Manures may be regarded as the food of plants, and 
this must be composed of the same elements as the plant 
itself, although they may exist in quite different forms 
and proportions. 

The adaptation of manures to the raising of a given 
crop can only be learned by first acquiring a knowledge 
of the constituents of the crop itself. 

A field, as before mentioned, may be fertile in regard 
to one crop, and barren in regard to another. 

What soils are denominafed calcareous? What gives names to 
calcareous clays, loams, and sands ? 

Does vegetable mold sometimes give character to soils? How 
much organic matter in garden mold? 

What are manures ? Of what must food of plants be composed ? 
How do we learn to adapt manures? 
6 



66 AGRICULTURAL CHEMISTRY. 

The defect in a soil which renders it poorly adaj^ted 
to produce a given grain, may often be readily supplied 
by a small exj^euditure of money, provided the particular 
defect is well understood by the farmer. 

Manures, as well as the plants which they are destined 
to feed, are composed of both inorganic and organic 
materials. 

The inorganic materials are mostly found in the earth 
from which plants grow, but whenever defective, they may 
be supplied by art. 

Organic food for plants is furnished by the decay of 
other plants, which have preceded them in the same soil, 
or it may be furnished in the form of farm -yard manures. 

Farm-yard manure is usually composed of hay, straw, 
and excrement of animals, mixed in some instances with a 
small quantity of earth. 

Manures are sometimes distinguished as animal, vege- 
table, and MINERAL. 

Animal and vegetable manures are used by plants only 
when they are decomposed into the form of carbonic acid 
gas, when it escapes into the atmosphere, from which it 
is imbibed mostly through the agency of the leaves of the 
plant; or, when those parts which are composed of nitro- 
gen are decomposed into ammonia, and afterward dissolved 

How to supply defects? Of what are manures, as well as 
plants, composed? Is inorganic food often needed to be supplied 
by art? 

How is their organic food furnished? Of what is farm-yard 
manure mostly composed? 

By what names are manures distinguished ? How are animal 
and vegetable manures changed before being used by plants? 

What does their decomposition produce? By what organs la 
their carbonic acid taken up? By what their ammonia? 



MANURES. 67 

in water, in wliicli it is mostly absorbed through their 
roots. 

Vegetable manures are furnished by such plants, as, by 
their decomposition, may furnish appropriate food for a 
succeeding plant, which may grow from the same soil. 
When plants decay in the soil from which they grow, 
during their period of decomposition, they contribute to 
form vegetable mold, or mold. 

To this class of manures belong hay, straw, weeds, 

POTATO-TOPS, GRASS, BUCKWHEAT, RYE, and CLOVER. 

Green gRx\ss and clover are sometimes plowed in 
while growing vigorously. By this means the whole crop 
is added to the soil as manure, but the value of such plan 
will depend upon the depth at which they are buried, and 
the kind of soil in which they are placed. 

In Great Britain, where artificial manures are most 
needed, the quantity of potato-tops, as manures, is much 
increased by breaking off the blossoms. 

Having learned the constituents of plants, and of the 
various soils from which they grow, we may be supposed 
in a measure prepared to decide correctly with regard to 
the supply of such defects in soils as render them unequal 
to supply that which is demanded for the perfect growth 
of a given crop. 

These defects in soils are accurately learned, only by 
the use of those tests, which chemistry teaches us to 
apply, except so far as one may be furnished with evi- 



How are vegetable manures furnished? During the period of 
decomposition of vegetable substances in soils, what do they 
produce? 

What belong to this class? How is green grass and clover 
sometimes treated? How is the value of potato-tops increased? 



68 AGRICULTURAL CHEMISTRY. 

dence by observing the cliaraeter of the vegetable and 
animal matter which is allowed to decay in it. 

Flesh of animals, by its decomposition, produces am- 
monia, and this substance serves to furnish materials for 
the formation of the nitrogenous portion of plants. 

The fat of animals and the largest portion of vegetables, 
by their decomposition, produce carbonic acid. This con- 
tributes to build up those portions composed of carbon, 
whether it be for the woody fiber of the stem, or the 
starch, which is the principal material found in the 
various grains of pith, or in the roots, or gum, which is 
dissolved in the sap, and sometimes exudes from the bark, 
or cuticle ; or sugar, which is also dissolved in the sap of 
many trees, or plants, from which it is procured by the 
process of evaporation by boiling ; or oil, which is abund- 
ant in the seeds, and fruit, of a large number of common 
trees and vegetables. 

The decomposition of any one of those substances which 
are built up of carbon, which has been derived from car- 
bonic acid, inasmuch as they furnish this material, con- 
stitute the proper food for plants when thus disposed of. 

When a soil, then, is defective in carbon, or nitro- 
gen food, the proper remedy will be readily under- 
stood. 

The refuse portions of almost any animal, or vegetable, 
may be employed as manure, but if we are not careful to 

How learn to supply defects of soils ? What does the flesh of 
animals by its decomposition produce? What does this furnish 
to plants? 

What does the fat of animals and the largest portion of vege- 
tables furnish? What does this contribute to build up? What 
else used as manure? 



MANURES. 69 

ascertain the chemical properties of such substances, as 
well as of the plant we propose to raise, injury, instead 
of benefit, is done to the crop. 

Dead Fish, which have been cast upon the shore of 
seas, or lakes and rivers, are sometimes used with profit 
in enrichino- soils. These can not be used with advant- 
age, without first being mixed with earth, or marl, so as 
to form a compost, and this should be turned over sev- 
eral times before it is prepared for use as a fertilizer. 

2^itrogen, or ammonia, must be furnished to most plants 
in order to their perfect growth, but quite different pro- 
portions are demanded by different plants. 

This element is most commonly furnished by the liquid 
portion of fcirm-yard manure, and by the decay of animal 
substances. 

It is of little consequence from whence these substan- 
ces are derived, provided they are not furnished in such 
concentrated form as to injure the plant by their caustic 
properties. 

AYhen farm-yard manure, and the other common sources 
of these substances, do not furnish the necessary supply 
of nitrogen food, recourse may be had to guano. 

Guano, a bird manure, is imported from islands near 
the coast of Peru. Birds which frequent these islands 
subsist almost entirely upon fish. Their excrement is 

What cai-e must be observed when dead fish are used? Do all 
plants require like proportions of ammonia? 

AVhat is its most common source? In what condition is it used 
by plants ? 

"What precaution in its use? What can we have recourse to 
when common sources fail ? 

What is guano? On what do birds subsist, which produce 
guano? 



70 AGRICULTURAL CHEMISTRY. 

dropped in a climate where rain is almost unknown, and 
where the atmosphere is so dry that but little loss of 
its soluble portions is sustained. This valuable fer- 
tilizer is brought from these islands by whole ship- 
loads. 

After being applied to land, if exposed to much rain, 
or even a moist atmosphere, much of the ammonia which 
it contains is lost by evaporation, unless care is taken to 
retain it in the soil. 

This is best accomplished by plowing it in to consider- 
able depth, when but small quantities will be brought into 
relation with the plant, or the atmosphere during the first 
season, otherwise the crop may be injured by its strength. 
or the caustic properties of its ammonia. 

Guano has become widel}- known, and much used as a 
manure on account of the fertility which it has been 
found to impart to such soils as had been regarded as 
worn out, and rejected as unfit for cultivation. 

The fact should not be lost sight of, however, that 

POULTRY DUNG, STABLE MANURE, and NIGHT-SOIL, may 

mostly be used for the same purpose, and that the one 
adds to the wealth of the farmer by its importation, ^hile 
the other adds to the wealth of the country as well as of 
the farmer, by saving the amount paid to the country 
where it is naturally produced. 

Night-soil is among the most valuable of manures, 
provided the methods for its preparation, and use are well 
understood by the farmer. Night-soil has long been used 



Wliy naturally preserved? What precautions when applied to 
land ? What does it impart to soils? 

What are home substitutes for guano? Why should these be 
sought in preference to guano? 



MANURES. 71 

by the Chinese as a fertilizer, and this may account for the 
hirge popuhition which is sustained in that country. 

When properly used, it has been found to increase the 
crop upon a given field, at least three-fold. If a field had 
produced but eight bushels of grain, the yield would at 
once be increased to twenty-four bushels. 

In addition to this increase of the produce of a district, 
by proper care of night-soil, the health of its inhabitants 
may be promoted by this disposition of it. 

If such substances are allowed to decompose and escape 
into the atmosphere, a noxious gas is furnished, which is 
injurious to the health of the inhabitants of the neighbor- 
hood. 

The same means that are available for retaining such 
exhalations, are also efi"ectual for preserving them, and 
storing them up, so that they may be used as manures, 
at such times as may be desired. This is most easily 
accomplished by mixing with them a small quantity of 
charcoal, prepared muck, or some other good absorbent. 

The product of this mixture is called Poudrette. 

In order to render this method most efi'ectual, a small 
quantity of the substance used as an absorbent, must be 
added every few days. 

When this method is practiced, no odors will be found 
to rise from the vault, as all gases are taken up by the 
absorbent, as soon as they escape. 

Ill what country has night-soil been long used ? How much 
does it increase tiie produce of a field? 

What other purposes served by its retention by absorption? 
How is this elfecfed? 

What is the product of this mixture called? What care in 
using the proper absorbent? Why does this method prevent odors 
irom vaults ? 



72 AGRICULTURAL CHEMISTRY. 

PouDRETTE, like guano, must be used only after being 
mixed with some absorbent, else the crop will be injured 
by the strength of the ammonia. The absorbent may as 
well be a portion of the soil in which it is to be placed. 

Poultry-house manure is much like guano in its 
properties as manure, and may be used in the same way. 
Its value is greatly increased by constant care, in adding 
an absorbent at very short intervals to the floor of the 
poultry-house. 

Much of its value is soon lost, in a moist atmosphere, 
by evaporation and leaching. 

Hog manure, on account of the rich quality of the 
food of swine, is of a superior quality, when properly pre- 
pared. 

Its value is greatly increased by furnishing vegetable 
mold, muck, or charcoal, to the sty ; for swine will work 
this over, and by mixing it thoroughly, save much labor 
to the farmer. 

The manure of swine at slaughter-houses is peculiarly 
rich, as they are often fed upon blood, and other animal 
food, which render it very rich in nitrogen and the phos- 
phates. Its ammonia is retained by mixture with absorb- 
ents, and this also protects the plant from injury. 

Sheep manure is less valuable, on account of the large 
proportion of nitrogen and mineral constituents which are 
appropriated in the formation of wool. 

What, care must be observed in using poudrette ? What may 
the absorbent be ? 

What is poultry-house manure like? How may its value be 
increased? How naturally soon lost? 

Why is this manure of superior quality? What is the manure 
of swine at slaughter-houses rich in ? What of sheep manure ? 
Why less valuable ? 



MANURES. 73 

Bones contnin gelatin, and this being a nitrogenous 
substance, ammonia is produced by its decomposition. 
(See page 45.) 

They also contain lime and phosphoric acid, both of which 
belong to the class of inorganic manures. (Pages 25 and 29.) 

In those countries where land is highly cultivated, on 
account of a necessity for its supporting a large population, 
many substances which have been unknown to us for such 
purposes, are used as manures. Among these are saw- 
dust, spent tan-bark, woolen rags ; waste of woolen fticto- 
ries, paper mills, and binderies, hair, and soot. 

Charcoal has been long used by farmers in place of 
manure, but with too little knowledge, (in some instances,) 
with regard to the manner in which it acts. 

Charcoal is composed of nearly pure carbon, but does 
not contribute, like manures proper, to the growth of 
plants, by its own decomposition. 

The value of charcoal resides in its remarkable power 
to absorb from the atmosphere, and to condense within its 
pores, those gases from the atmosphere and elsewhere, 
which serve as food for plants. 

It has been computed that charcoal will absorb and 
condense ninety times its bulk of ammonia, thirty-five 
times its bulk of carbonic acid, but only nine times its 
bulk of oxygen, and seven times its bulk of nitrogen. 



What do bones contain? What does gelatin by its decomposi- 
tion produce? What else do they contain? 

AVhat substances used in countries where land is highly culti- 
vated ? Has charcoal been used in place of a manure ? 

Does charcoal itself contribute to the growth of plants ? In 
what does its value reside ? 

How much ammonia will charcoal absorb? How much carbonic 
acid — oxygen — nitrogen ? 

7 



74 AGRICULTURAL CHEMISTRY. 

It also absorbs from tlie atmosphere large quantities of 
watery vapor, whicli it retains in soils, and by this means 
contributes to retain a certain quantity of moisture during 
dry seasons. 

These properties are possessed in a higher degree by 
those specimens which are finest, and consequently con- 
tain most pores, and in a lower degree by the more loose 
and spongy. 

It has been estimated that a cubic inch of charcoal must 
have at least an absorbing surface of one hundred square 
feet. It is upon the interior surface of the pores that 
gases are condensed, -and the quantity absorbed is in pro- 
portion to the extent of this surface. 

The value of charcoal in preserving meats, and in re- 
storing those which are tainted, depends upon its power 
to immediately remove the results of their decomposition. 

Soot contains much carbon, and may be used in some 
instances in place of coal. It also contains some sulphur, 
and this serves as food for plants. 

The ammonia which it contains is mostly in the form 
of a sulphate, which is not volatile, and consequently does 
not evaporate when applied as a top-dressing. The odor 
of its sulphur, when thus used, serves as .a good protection 
against some kinds of insects. This is the source of its value 
when thrown upon young cabbage plants, and melon vines. 

What else does it absorb? To what does this contribute? What 
specimens of charcoal are most valuable? Why? 

What is the absorbing surface of a cubic inch of charcoal ? On 
what does the value of charcoal in preserving meats depend? 

What does soot contain? What may it sometimes be used in 
place of? 

In what form is the ammonia which it contains? W^hat pur- 
pose does the odor of sulphur serve? 



INOKGANIC MANUEES. 75 



CHAPTER XVIII. 

INORGANIC MANURES. 

The inorganic or mineral manures exist naturally in 
sufficient quantity in many soils. In some, however, they 
are so defective as to require their artificial supply. 

These manures act in a variety of ways, in addition to 
their use as furnishing food for the inorganic part of 
plants. 

Some of these perform an office in changing both the 
organic and inorganic manures which exist in the soil, and 
thus fit them for absorption by the roots and leaves, in 
order that they may be assimilated by the plant. 

Others seem only, or mostly, to change the mechanical 
condition of soils, and still others are useful as absorbers 
of carbonic acid and ammonia. 

Some of the inorganic manures are furnished to the soil 
by the decay of organic manures, or the decay of certain 
trees and plants. The ashes of such substances are left 
after their decomposition, in the same manner as when 
their organic portion has been burned away in the fire. 

If the crop which is grown from any given piece of 
land be at once returned to it as manure, such field will 
constantly increase in fertility. 

Is inorganic food sufficient in most soils? In what ways do 
tbey act ? 

How are some inorganic manures furnished to soils? What 
if a crop be at onct' returned to a field? 



7($ AGRICULTURAL CHEMISTRY. 

The cliief object in cultivating land, however, is not 
realized to the farmer by this process, for; like the miser, 
much is accumulated by the land, which is not made 
useful for any purpose whatever. 

When we have learned the constituents of any plant, 
we are prepared to adapt it as a fertilizer in the most 
economical way. 

Example. — The ashes of the potato contain more pot- 
ash than any other inorganic substance, while the ashes 
of clover contain lime as a principal ingredient. 

It is apparent, then, that each of the green crops, when 
used as manure, has a definite value with regard to the 
crop we propose to raise. As the ashes of wheat and rye 
contain a large proportion of potash and soda, and that 
of oats a larger proportion of lime than either of these, 
we are enabled to apply these substances in a way that 
will contribute to the production of these grains. 

Potash and soda have been found in all clays, when 
they have been sought for, but their proportion is quite 
different in different localities. 

LiTME, in some of its forms, is the most constant and 
important of the inorganic constituents of soils. The most 
common form is that of a carbonate, as lime-rock, chalk, 
and marble. (See p. 62.) 

The next form is as gypsum, or sulphate of lime. 



Is the chief object in cultivating land realized by this process? 
What teaches how to adapt a fertilizer most economically ? Give 
an example. 

Has each green crop a definite value as a fertilizer? Mention 
the special value of some, and why. Where is potash and soda 
always found? 

Which is the most constant and important of the inorganic con- 
stituents of soils? Which is the next most important? 



INORGANIC MANURES. 77 

QuiCK-LTME, an oxide, Is produced by heating either of 
the carbonates, by which their carbonic acid is expelled. 
(See p. 26.) 

Lime is a principal inorganic ingredient of several 
grains and grasses, as oats and red-clover, while it exists 
in still larger proportion in lucerne. 

It exists in very large proportion in the bones of ani- 
mals, and in the shell, or outer covering of mollusks, as the 
oyster and clam, and of the Crustacea, as lobsters and crabs, 
and mostly in the form of a phosphate and a carbonate. 

There is no substance used in agriculture that serves 
such variety of purposes, as lime. 

In addition to furnishino; materials for animal and veue- 
table structure, it is used : 

1. To hasten the decomposition of other substances in 
soils. 

2. To remove excess of acids. 

3. To cause the mineral matter in soils to crumble. 
Lime being itself an alkali, which, when in excess, is 

injurious to soils, unites with acids, which are also inju- 
rious, and thus forms another substance which is called 

a SALT. 

Salts are the principal forms in which inorganic mate- 
rials serve for the support of plants, either by contribut- 
ing to their structure, or by changing the mechanical 
condition of soils. ^ 

Lime being an active decomposing agent, serves to 

How is quick-lime produced? In what grains is lime most 
abundant? 

Where in animals does lime exist? What different purposes 
does it serve in agriculture ? 

How useful in soil which contains acids? In what principal 
form is inorganic material used by plants ? 



78 AGEICULTURAL CHEMISTRY. 

hasten the decomposition of organic matters, and to sep- 
arate them from the inorganic materials with which they 
are associated, when they escape in the form of gases, and 
are then in a condition to be absorbed by the roots and 
leaves of plants. 

The action of lime upon organic substances secures 
their decomposition into the same elements as those of 
which they were originally constructed. The lime does not 
unite with animal and vegetable matter, and thus produce a 
third substance, as when it acts upon inorganic matter, or 
unites with acids. 

When it acts upon the fat of animals, or upon the 
substances formed of carbon which exists in plants, the 
substance produced is carbonic acid. 

By its action upon the flesh of animals, or any other 
organic substance which contains nitrogen, the product of 
such decomposition is ammonia. 

When the substance subjected to its action is formed of 
both carbon and nitrogen, the result will be both carbonic 
acid and ammonia, and, at the same time, wafer. 

The decomposition, then, of all organic substances, of 
whatever kind, will produce at least one, and, sometimes, all 
of these three substances, viz. : water, composed of oxygen 
and hydrogen; CARBONIC ACID, of carbon and oxygen; 
and AMMONIA, of hydrogen and nitrogen. 



\ 



What is the effect of lime on organic matter? What substan- 
ces does this decomposition produce? 

Does lime ever unite with animal and vegetable matter? Does 
it unite with inorganic matter? 

What is produced when it acts upon the fat of animals ? What 
when it acts upon their flesh? 

What will the decomposition of all organized substances pro- 
duce? 



INOEGANIC MANURES. 79 

As lime forms no part of these compounds, it is appar- 
ent that it acts only as an agent in securing these changes, 
and thus fitting them for the support of plants. 

Such soils as contain an injurious quantity of acids, 
which render them fitted for the support of inferior 
plants only, as sorrels and other weeds which are them- 
selves injurious to useful plants, will be rendered fertile 
with regard to most grains, by the addition of a small 
quantity of lime. Such lime must b^ in a form that does 
not already contain an acid. The form used for this pur- 
pose is quick-lime. 

IxNORGANic COMPOUNDS are so acted upon by lime as to 
crumble down into fine particles. By its union with some 
compounds of this class, both are rendered soluble. 

By its union with Silica, it forms a silicate of lime. 
The silica in this instance seems to take the place of an 
acid. 

The MECHANICAL changes which are produced in soily 
by the agency of lime, are also calculated to facilitafe cer- 
tain CHEMICAL changes, for the finer particles being thus 
exposed more fully to the influence of the atmosphere, 
will more readily undergo that chemical change which is 
called oxidation. It is also thus better prepared to absorb 
nutritive material for plants, from the atmosphere. 

The addition of a small quantity of lime to a compact 

What the use of lime, then, when thus used ? What its use in 
improving lands which contain acids? 

What, must such lime not contain? What form should be used? 
What is the action of lime on inorganic compounds? 

What substance is thus rendered soluble? What does silica 
seem to take the place of? What purposes do the mechanical 
changes which it effects, serve? 

What is its effect upon compact clay ? 



80 AGRICULTURAL CHEMISTRY, 

clay, or aluminous soil, will render it loose, and thus fitted 
for easy cultivation. 

The quantity -of lime which is proper to use, should be 
carefully regarded in each particular case. 

A proper quantity will greatly facilitate the decompo- 
sition of organic substances, while a larger quantity may 
produce too rapid decomposition of the same substances, 
and thus induce a useless waste of the best materials for 
the support and growth of the plant. 

An excess of lime will have the effect to exhaust a soil, 
for that which is not readily used by the plant, escapes as 
gas into the atmosphere, and is lost to the field which it 
is designed to improve. 

These gases may be stored up and used at a future time, 
provided some absorbent is furnished, or exists naturally 
in the soil. 

The best artificial absorbent which can readily be pro- 
vided for this purpose, is charcoal. 

The most common natural absorbents are clay and alu- 
mina, especially during a long dry season, during which 
much ammonia is stored up for future use in the pores of 
these substances. 

Lime should be used with much care, especially when 
associated with animal manures, as an excess will cause a 
rapid and wasteful discharge of ammonia. 

Care should be observed to procure lime which is 

Should its quantity here be carefully regarded? Why careful 
about quantity when added to organic substances ? 

How may gases which escape be stored up ? What is the best 
artificial absorbent? 

What are the most common natural absorbents? Why should 
lime be used with care when it is associated with animal manures? 

What care is necessary in selecting lime? 



INORGANIC MANURES. 81 

free from impurities, the most common of wliicli is mag- 
nesia. 

The best lime for enriching soils is produced by the 
burning of shells, for such is free from the noxious agen- 
cies which are elsewhere found. 

Sulphate of lime, or gypsum, is also called Piaster 
of Paris, because it exists in abundance in the rocks which 
underlie the city of Paris. 

Gypsum is made to serve two important purposes as 
a fertilizer, for the sulphur which it contains, supplies that 
element to plants. 

Unlike the oxide, or quick-lime, it acts as an absorbent 
of ammonia. 

This quality indicates the utility of sprinkling it about 
stables, privies, and poultry-houses, where it absorbs nox- 
ious gases, and by this means renders such places more 
healthful, and better fitted for the abode of animals. 

When gypsum is used to excess, it promotes the growth 
of sorrel ; for the land is rendered sour, by the separation 
of lime for the use of the plant, while the acid is left free 
in the soil. This condition is readily corrected by the 
addition of quick-lime. 

Chloride of lime may be easily produced by the mix- 
ture of lime and salt, or by slacking quick-lime by the 
use of sea-water. 

It may be used to absorb ammonia and other gases, and, 

What is the most common impurity? From what is the best 
lime produced ? What purposes does gypsum serve ? How unlike 
quick- lime? 

Why should it he sprinkled about stables? What is its effect 
when used to excess ? How is this condition corrected ? 

How is chloride of lime produced? For what purpose is it 
used ? 



k 



S'^ AGKICU LTUHAL UHEM ISTK V. 

like quick-lime, for the decomposition of animal and yege- 
table substances. 

Phosphate of lime, or bone earth, wliicli is formed 
of phosphoric acid and lime, is one of the most common 
constituents of animal and vegetable substances. 

It is called bone earth, because it is the form of lime 
which exists most largely as an earthy constituent in the 
bones of animals. 

Phosphoric acid exists in large proportion in the ashes 
of various grains. It forms about one-half of the ashes 
of wheat, buckwheat, rye, corn, and oats ; but in slightly 
less proportion in barley, peas, and beans. It also exists 
as an important substance in potatoes and turnips. About 
one-fourth of the ashes of milk is composed of phosphoric 
acid. 

The various methods by which phosphoric acid is 
removed from soils, and the limited number of natural 
methods for its return, render the study of the relations 
of this substance to soils and plants, as well as animals, 
among the most important in agriculture. 

Every bushel of wheat removed from a farm, takes away 
a little more than half a pound of phosphoric acid ; or 
each hundred bushels of wheat removes nearly sixty 
pounds of this acid. 

It has been estimated that each cow which feeds in a 
pasture during a whole summer, will remove not less than 

Of what is phosphate of lime formed? Where abundant in 
animals ? Where does it exist in grains? 

1 In what grain does it form much of the ashes? In what others 
is it an important substance? 

What is its proportion in the ashes of milk ? Why should the 
relations of phosphoric acid be carefully studied? 

How much does every bushel of wheat remove? How much 



UllGAXlC MAN UliEB. 83 

fifty pounds of bone earth. As one thousand pounds is 
thus removed by each twenty cows, it becomes apparent 
that the exhaustion of pasture lands is very rapid, so that 
in a few years a fertile pasture may be reduced to a bar- 
ren waste, and this may be true, while it contains all the 
other materials which are demanded in order to constitute 
a fertile field. 

It has also been estimated that the removal of bone 
earth from the farms of some of the older states, has 
caused more emigration than all other causes combined; 
and this, when a limited knowledge of the constituents of 
soils, and of the methods for ascertaining and remedying 
defects, would have rendered the restoration of such fields 
both certain and economical. 

The principal source from which phosphoric acid may 
be furnished to exhausted fields, is by the use of bones 
of animals, for these contain a large proportion of phos- 
phate of lime. 

Bones seem to be the receptacles in which large quan- 
tities of phosphoric acid are stored up, from whence it may 
be used by plants at such times as it may be required. 

Bones, when dried, consist of about two parts of inor- 
ganic" material, most of which is phosphate of lime, and 
one part of organic matter. 

The organic portion is mostly composed of gelatin, a 

does each cow remove? Each twenty cows? What is the effect of 
this removal on fields? What is the source of most emigration ? 

How could this have been remedied ? How may phosphoric acid 
be returned to exhausted fields? 

Where is phosphoric acid stored up in animals? What do dried 
bones consist of? What is the organic portion mostly composed 
Of? 



Q4 AGiUCULTUKAL CHEMISTKY. 

compound which consists principally of nitrogen, and 
which, by its decomposition, like other compounds which 
contain nitrogen, produces ammonia. 

Bones are sometimes crushed in mills, and then sepa- 
rated into heaps, and such heaps are composed of frag- 
ments of similar size. These are distinguished by dealers 
as inch, and half-inch bones, and bone-dust. 

Specimens of crushed bones are selected as fertilizers, 
in accordance with the rapidity of the action which is 
desired. Bone dust will act the most rapidly, but its 
action will accordingly be soonest exhausted. 

Whole bones are sometimes used for enriching soil, but 
this is the least desirable method, for their decomposition 
is too slow to produce the best results. 

It has been estimated that one bushel of bones, properly 
prepared, will produce more results as a fertilizer in five 
years, than ten bushels used whole, or but slightly broken. 

Bone black is produced by burning bones in a retort, 
or in such way as to protect them from the atmosphere 
during the process. By this means all the organic portion, 
except carbon, will be expelled. The product of this pro- 
cess is called bone black, or ivory black, and consists of 
inorganic matter, and carbon of the bones. 

The nitrogen having been disposed of, no ammonia can 
be formed by its decomposition. This is compensated for 

What does this produce by its decomposition ? How are bones 
prepared for market? How distinguished by dealers? 

What condition preferred as fertilizers? Why are not whole 
bones more used? 

What is the comparative value of whole bones and bone dust? 
How is bone black produced? 

By this process what is expelled? What does the product con- 
sist of? 



INORGANIC MANURES. 85 

by tlie carbon, which is retained in a form which renders 
it a good absorbent in the soil. The whole may be reduced 
to fine particles much more easily than before it was charred. 

The decomposition of bones may be secured by com- 
posting them with ashes. The strongest unleached ashes 
should be used for this purpose. The bones should be 
placed in some water-tight vessel, in layers of a few inches 
in thickness, alternating with layers of ashes. These 
should be kej)t constantly wet. 

If they become dry, or approach that condition, they 
will send off an offensive odor; and this is accompanied 
by loss of ammonia, and consequently loss of value. 

The reduction of bones by this method will usually 
require a year. At the end of that time they may be 
easily washed away, when they will be readily appropri- 
ated by soils and plants, while the ashes will be of nearly 
equal value as a fertilizer. 

Magnesia exists in small quantity in the ashes of vege- 
tables ; but its presence is so constant in soils as rarely to 
require its application to fields, to fit them for better sus- 
taining a crop. 

Wherever required, it may be applied in the form of 
magnesian lime, but this combination of magnesia already 
exists in many soils, in such proportion as to be injurious 
to its fertility. 

How is the loss of nitrogen compensated for? In what other 
way may the decomposition of bones be secured ? Describe the 
method. 

What if allowed to become nearly dry? How much time will 
this reduction of bones require ? What their condition at the end 
of a 3'ear? 

Does magnesia exist in the ashes of vegetables? Is its artificial 
application often required? How is it, applied when required? 



86 AGRICULTURAL CHEMISTRY. 

Sulphuric acid is a very important constituent of some 
vegetables, especially of oats and the root crops. 

For this reason it is sometimes defective in soils which 
have been long used for potatoes, and other root crops. 

In such instances, the most convenient and economical 
method for supplying the defect, is by the use of plaster 
of Paris, from which the sulphuric acid is abstracted, and 
the lime is left free, in which condi-tion it may serve for 
the mechanical reduction of soils. 

It is sometimes desirable to add the sulphuric acid 
alone, esiDCcially wdien the use of lime would be injurious, 
but in such instances it must be largely diluted with 
water. 

Sulphuric acid is sometimes added to compost heaps, 
in order to secure the change of ammonia, which is vola- 
tile, and escapes easily into a sulphate, which is not vola- 
tile, but is readily dissolved in water, and thus absorbed 
by plants. 

Those w4io are employed in manufacturing fertilizers 
have sometimes paid five and even seven cents a pound 
for sulphate of ammonia, in order to add it to their prod- 
ucts ; while the farmer who is not informed with regard 
to the value of this compound, and the cheap and easy 
method of producing it, will throw away vast quantities 
of the riches of his soil. 

Silica, or sand, nearly always exists in soils in sufficient 



In what crops is sulphuric acid an important constituent? How 
is it most econoiiiically supplied when required? 

What takes place when gypsum is used? When may it be 
necessary to add sulphuric acid alone? 

What caution is necessary when it is used? For what purpose 
is sulphuric acid added to compost heaps ? Describe the utility 
and economy of this plan. 



INORGANIC MANURES. 87 

quantity, but not in a proper condition for the support 
of plants. When the weakness of the straw of grains in- 
dicates a demand for silica, the rule is not to add silica 
to the soil, but such alkalies as, by combining with it, 
;\vill produce silicates ; for these are soluble, and readily 
jtaken up by the roots of plants. 

Sand is also useful as a mechanical manure, for when 
mixed with stiif clay, it loosens ■ such soil, and renders 
it better fitted for cultivation. 

Chlorine is a necessary constituent of plants, and when 
not present in soils in suJB&cient quantity, it may be sup- 
plied in the form of CHLORIDE op sodium, (common salt,) 

or CHLORIDE OF LIME. 

Chlorine is naturally supplied in abundance to such 
plants as grow near the sea-shore. 

Oxide of Iron is one of the most commonly present 
substances in soils, and is seldom, if ever, required as a 
manure. 

There are two common oxides of iron — the protoxide 
and the peroxide. 

The protoxide exists most largely in common deep 
soils, and is always injurious to vegetation. 

The peroxide is not only inoffensive, but actually 
necessary to a fertile soil. 

The protoxide of iron may be readily changed to the 

Is snnd often required to be applied artificially? When straw 
of oirain is weak, why not add silica? What is the proper course? 

What is the utility of sand with stiff clay? How may chlorine 
be supplied to plants? 

Where is it naturally supplied? Is oxide of iron common in 
soils? In what two forms? 

Which is injurious to vegetation? Where does protoxide of iron 
exist ? 



SB AGRICULTURAL CHEMISTRY. 

peroxide, by turning up the soil which contains it quite 
often, so as to expose it freely to the oxygen of the at- 
mosphere, from which it imbibes an additional atom of 
this element. 

Oxide of Manganese is not recognized as an essen- 
tial constituent of plants or soils, and is not commonly 
taken into the account in manuring land. 



CHAPTER XIX. 

DRAINAGE. 

Drains, or under drains, serve a variety of purposes, 
and are constructed in different ways. They are mostly 
used for the purpose of removing surplus water, in order 
that land may be cultivated. While this is being accom- 
plished, other purposes are very often unconsciously real- 
ized by the f\irnier. 

A necessity for the removal of surplus water arises from 
a variety of sources, the principal of which are the pres- 
ence of springs, or a subsoil which prevents the trans- 
mission of water, either upward or downward, with the 
facility demanded, in order to render the surface soil pro- 
ductive. 

A soil composed mostly of clay may itself be sufficiently 
compact to demand the use of this means for the removal 
of water. 

How may protoxide be changed to the peroxide? Is oxide of 
manganese an essential constituent of soils? 

What purposes do drains serve? What soils require tliem 
most? 



DRAINAGE 89 

Clay is sometimes associated with small quantities of 
oxide of iron. Such stratum is often so compact as to 
prevent the transmission of water, nearly as efiectually as 
the most solid rocks. 

Great advantage may be conferred in such cases by sink- 
ing shafts, or wells, to such depth as to reach a layer of 
gravel, into which water may be received, and thus con- 
veyed away, or absorbed. 

Drains are commonly placed at a depth of two and a 
half to five feet; and the purposes they serve, at these 
diiferent depths, vary mostly in their degree of action ; and 
their depth will also suggest the distance from each other 
at which they should be placed, for the influence of a 
drain will extend in accordance with its depth. 

Such drains as may be useful for a considerable number 
of years, may be cheaply arranged by placing stones of 
four to six inches in diameter, along the sides of a trench, 
and laying slabs, or other cheap boards over them, leaving 
a space between the rows of stones, through which the 
water can flow. 

An early method of constructing drains, was by placing 
branches of trees in the bottom of the trench, filling it to 
considerable depth, and covering the earth immediately 
upon them. Others placed small stones in the bottom of 
the trench, and covered them in the same manner. 

This plan served the purpose of a stratum of gravel, 

though in a less degree. If these had been covered with 

flat stones, or plank, in order to prevent the packing of 

earth into the interstices, their utility would have been 

greatly prolonged. 

When are shafts or wells required? At what depth are drains 
commonly placed? How far apart? How may they be cheaply 
arra nged ? 



90 AGRICULTURAL OHEMLSTRY. 

A more recent method is by the use of earth baked 
like earthenware, which may be made of any form and 
diameter, and in sections of any length desired. 

Drainage is mostly practiced for two purposes : 

1. For the removal of surplus water from a locality, or 
from a soil ; and, 

2. For the purpose of bringing the materials of which 
a soil is composed into such relation with the atmosphere 
that its elements may contribute to the production of cer- 
tain changes in the soil, and thus render it better fitted 
for the suj:)port of plants. 

Those soils which demand this method for their im- 
provement are mostly formed of clay, or contain a very 
large proportion of this material. 

Clay may be an essential ingredient of the surface soil, 
or, it may contribute to form a compact layer beneath the 
surfiice, and thus constitute a subsoil, which, from its com- 
pactness, may prevent ihe natural development of the plant 
by impeding the proper descent of their roots. 

Such materials can not long remain as a hard layer, 
after the water which it contains has been drained off, so 
as to admit of the descent of the atmosphere ; for this 
element is known to pervade, not only water in streams 
and lakes, whenever their surface is exposed, 'but also 
the earth to a considerable depth, when it is not satu- 
rated with water, and when not consolidated into a hard 
layer. 

The PROTOXIDE OF IRON, which is often an ingredient 
of such hard stratum, is not only injurious, when in union 

What our present method for their construction ? For what 
purposes are drains introduced? 
What foils require drains? 



DEAINAGE. 



91 



with clay, by rendering it more compact, but is always 
injurious to plants in any situation. 

When such mixture is brought to the surface by the 
use of the plow, or when exposed to the atmosphere 
through the agency of so far removing water from the 
soil as to admit the access of air, the protoxide of iron, 
which is injurious to plants, by receiving an additional 
atom of oxygen from the atmosphere, is converted into a 
PEROXIDE, which is a necessary material for their support 
and growth. 

Chemical changes in soils which contain either protoxide 
of iron, or lime, are greatly retarded by the presence of 
surplus water. Such changes may be either proinotcd^ or 
retarded^ by the presence of water, and this will be in 
accordance with its amount, and the nature of the soil, 
for some soils are much more injuriously affected by drouth 
than others, and those lands which are most improved by 
frequent variation in the amount of water they contain, 
are those which are composed of lime, with clay, and a 
small quantity of iron. 

Although the necessary action of oxygen upon a soil 
is prevented by excess of water, some moisture is abso- 
lutely demanded for this purpose. 

When a soil is too dry, its materials can not be brought 
sufficiently under the influence of chemical agencies to 
admit the necessary changes, although the amount of 
watery vapor in the atmosphere even, is often sufficient 
for this purpose. 



What does removal of water admit to soils? What change in 
iron does this secure? 

What lands are most improved by frequent variation of amount 
of water they contain ? 

When a soil is too dry. th^ influence of what ao-encies are cut off 



92 AGRICULTURAL CHEMISTRY. 

When a soil is rendered loose, by draining away the 
surplus water which it contains, the atmosphere will gain 
access to its particles, to considerable depth, and thus 
become an agency in effecting certain mechanical changes 
in its condition. 

Such mechanical changes in a soil will admit of those 
necessary chemical changes which are secured only through 
the agency of the atmosphere. This process also admits the 
absorption, by the soil, of carbonic acid and ammonia, which 
are here stored up, in order to become food for plants. 

Drainage not only induces changes in the inorganic 
materials in soils, but promotes the decomposition of or- 
ganic matter ; for too much water prevents these changes, 
and renders this kind of food for plants quite useless, as 
means for promoting their growth. 

Water may serve as a necessary solvent of the various 
materials which are naturally destined as food for plants, 
or it may act injuriously, by washing them away, so as to 
place them beyond the reach of the plant. 

Drainage does not deprive a soil of the necessary 
amount of moisture, for it increases the facilities for its 
circulation, and thus renders it the bearer of those sub- 
stances which are required by plants, as well as fits them 
for their support. 

The roots of most plants extend to a considerable dis- 
tance through the soil, those of some extend along near 
the surface, and others penetrate downward several feet, 
many of them not less than two or three. 

A plant may grow luxuriantly through the early part 

What other than chemical changes are secured by drainage? 
What double purpose does water serve? 

Does drainage deprive a soil of necessary moisture? Why not? 



DRAINAGE. 93 

of a season, and then droop, and ftiil to mature, and this 
because its roots have penetrated through a superficial soil, 
which has thus far furnit^hed it with the necessary nutri- 
ment, but later in the season have penetrated to a layer of 
hard pan, or to some noxious ingredient, which, by its 
poisonous qualities has arrested its devekipment. 

This often takes place when the remedy would be easy 
and effectual by the introduction of proper drains, so as to 
admit of the necessary chemical changes. 

A dry season is not without its utility, both to the soil 
and to the plant, for the observing farmer has long been 
acquainted with the fact, that a good crop is likely to 
succeed to a dry season. 

The principal source of this utility is in the condensa- 
tion of ammonia and of carbonic acid in the pores of such 
soils as are not already occupied by water; for although 
water is a good absorbent of ammonia, its office for this 
purpose is much better accomplished when in an attenu- 
ated condition, as in the form of vapor, or of snow-flakes. 

The circulation of water through a soil is indispensable 
to render it available as a means of conveying nutriment 
to giants, and this, (like the circulation of the blood in 
anihials,) does not so much depend upon its quantity, as 
upon the means which are provided for its transmission. 

The genial shower is of little, or of no use, to a soil, 
when it is already occupied by water which it can not dis- 
place ; and those valuable constituents which are brought 
down from the atmosphere, are thus carried away by the 
surface flow of water. 

What may cause plants to fail to mature ? What is the remedy ? 
What are the utilities of a dry season? How may the natural 
benefits of a shower be prevented? 



APPENDIX 



DIRECTIONS FOR USING APPARATUS. 

More complete directions for the use of apparatus, 
than are contained in this treatise, or in most of the text- 
books, as well as special directions for conducting each 
experiment, have been deemed proper. 

It is hoped that by this plan, some who may have 
omitted the introduction of experiments in the class-room, 
will no longer hesitate in the use of the-se invaluable aids. 

Those who may introduce experiments for the first time, 
will seldom fail, provided they are vigilant in observing 
all the directions which are found, both in their proper 
place in the text, and in these special directions. 

TKANSFERRING GASES. 

Before the effort is made to transfer gases from one 
vessel to another, it will be well for those who are entirely 
unaccustomed to this manipulation, to imitate the process 
by the use of atmospheric air, over a water-trough. 
This may be done in the following manner: 
Place a glass^ (inverted) on a shelf in the trough, in 
which the water rises a little above the shelf. This will 

-^ Straight glasses, of uniform diameter, are introduced in this work, in 
place of the bell glass, (whenever admissible.) as they are more economical, 
less easily broken, and can be turned up without transfer of gases. 

(95) 



96 AGRICULTURAL CHEMISTRY. 

leave the glass full of air, wliicli is there confined by the 
water, beneath the surface of which the edge of the glass 
rests. 

Another glass, which has been inverted while beneath 
the surface of the water, is raised till its edge is near 
its surface. The edge of the glass filled with air is then 
carried under the one filled with water. The top of the 
one containing air is now slowly inclined to one side, when 
bubbles of air will rise through the water, the same as 
when gases are transferred. 

The only object in repeating these manipulations before 
engaging in actual experiments, is to enable the operator 
to become familiar with the uses of the most simple appa- 
ratus, in order to avoid waste of gases. 



DIRECTIONS FOR THE SEVERAL EXPERIMENTS. 



EXPERIMENT I. 
PREPARATION OF CHLORINE. 

Put one part of oxide of manganese, and three to seven 
parts of chlorohydric acid, in a retort or flask. (See p. 28.) 

That the precise quantity of acid is unimportant, may 
be inferred from the diversity of proportion directed by 
different authors. 

When a gentle heat is applied, the chlorine will be seen 
to rise in the retort, being of a greenish 3^ellow color. 
It may be gathered by displacement of dry air, and its 
ability to support combustion tested. Or, it may be re- 



APPENDIX. 97 

ceived into a jar of cold water, for this will absorb twice 
its bulk of the gas. 

This is the most convenient method for testing the bleach- 
ing properties of chlorine; and this effect may be observed 
by placing in the solution some strips of colored cloth, 
for it is found to remove such colors as have been pro- 
duced, either by vegetable or animal substances. 

EXPERIMENT II. 
PEEPARATION OF PHOSPHORIC ACID. 

Ignite a few grains of phosphorus, in a capsule or 
watch-glass floating upon water, and cover immediately 
with a glass. While the oxygen of the contained atmos- 
phere is being rapidly consumed, or unites with the phos- 
phorus, the water rises rapidly in the glass. (See p. 29.) 

If prepared over water, the product, (phosphoric acid,) 
will be greedily absorbed, and may, like other acids, be 
tested by litmus. , 

When prepared over mercury, instead of water, the 
phosphoric acid will descend in flakes upon the surface 
of the fluid metal. 

A common glasB jar of the shops may as well be used, 
for the intense heat which attends the combustion of 
phosphorus, is quite likely to break the vessel used in 
this experiment. 

EXPERIMENT III. 
NITROGEN WITHOUT OPEN COMBUSTION. 

A piece of phosphorus upon the end of a glass rod, 
may be carried up into the bulk, and the open end placed 
in water. (See p. 35.) 

If the tube is not unnecessarily large, while the bulk is 
9 



98 AGEICULTURAL CHEMISTRY. 

of considerable size, so mucli of the oxygen of tlie con- 
tained air will be consumed in the time commonly occu- 
pied by a recitation, as to enable tlie class to observe that 
the water has risen in the tube, and occupied the place of 
the consumed oxygen. (See fig. 3.) 

Several hours (at least twenty-four) will be required to 
complete this process. The exact quantity of phosphorus 
used is unimportant, as all action will cease when the 
oxygen is consumed. 

Great care should be observed in handling phosphorus, 
as it takes fire by slight friction, or elevation of temper- 
ature, when exposed to the atmosphere. It should always 
be cut while under water, from which it should not be 
unnecessarily removed. 

EXPERIMENT IV. 

NITKOGEN BY OPEN COMBUSTION. 

This experiment is conducted the same as that for the 
preparation of phosphoric acid, and the same apparatus 
may be used. 

The two experiments may be conducted as one, provided 
the teacher prefers to do so, for the only difference con- 
sists in the observation of results. 

The plan for testing the gas is the same, and the results 
the same, when prepared by either method. 

EXPERIMENT V. 

TEST OE NITliOGEN GAS. 

The gas may be transferred to a gas bottle, (see fig. 5,) 
and then tested by lowering a taper into it, when it will 
readily be extinguished. 

A small animal, as a mouse, will soon die when con- 
fined in this gas. 



APPENDIX. 99 

EXPERIMENT VI. 
OXYGEN WITH CHLORATE OF POTASH AND MANGANESE. 

Mix one liundred grains of chlorate of potash with thirty 
grains of manganese. The manganese should jfirst be heat- 
ed, in order to expel what moisture it may contain, which 
may be done on a strip of sheet iron, over a spirit-lamp. 

A retort, or Florence flask may be employed, but the 
flask requires more care, as an additional tube must be 
used, which must be connected by a cork. 

When the gas begins to come ofi", the heat should be 
maintained nearly uniform as long as the gas escapes. 
The lamp should be slowly removed, which, if neglected, 
the retort will be liable to be broken from cooling too 
rapidly. 

The stopper should be removed, or the end of the tube 
raised above the water, in order to prevent its entrance 
into the retort, for, as it cools, a vacuum will be formed, 
which will be occupied by the water. 

One hundred grains of chlorate of potash will produce 
forty grains of oxygen, which will measure one hundred 
and eighteen cubic inches. 

EXPERIMENT VII. 
OXYGEN WITH OXIDE OF MERCURY. 

This experiment is conducted like the last, except that 
a bulb, or globe, is interposed between the reto^-^ 
glass, into which the mercury is conu. -.„, ..^xxc; the 
oxygen passes forward to the glass over the trough. 

More heat is required than in the former experiment, 
and the retort will consequently be more likely to be 
broken, a result which is not uncommon in either case, 



100 AGEIC.ULTURAL CHEMISTRY. 

for these experiments are liable to be undertaken at tlie 
expense of a retort. 

The last miiy sometimes be omitted, but its results 
should be carefully studied, as it is one of the most inter- 
esting experiments in chemistry. 

EXPERIMENT VIII. 
TEST OF OXYGEN. 

When a straight jar is used for collecting oxygen, it 
may be turned up without transferring the gas. 

A piece of charcoal, with an ignited point, held in a 
spoon or wire-forceps, may be lowered into the gas bottle, 
(see fig. 8,) when its combustion will become very rapid. 

This may be removed from the bottle, and several times 
returned, in order to prove that oxygen, like hydrogen, 
will not remain ignited, when the burning body is removed. 

EXPERIMENT IX. 

OXYGEN BURNS METALS. 

A watch-spring, or small wire, should perforate a cork 
which fits the mouth of a gas bottle ; and when ignited, 
it should be pushed down as rapidly as it burns away. 

EXPERIMENT X. 
PREPARATION OF HYDROGEN. 

The granulated zinc, or iron filings, are placed in the 
bottle ; (see fig. 10 ;) some diluted sulphuric acid is poured 
on, and the gas allowed to generate for a short time, in 
order to expel the atmosphere from the flask, otherwise 
an explosion may take place. 

The funnel tube should be carried down to the bottom 



APPENDIX. 101 

of the jar, or into the liquid, in order to prevent tlie 
escape of gas. 

The dikited acid may be added through the funnel tube, 
as required, which will be indicated by the diminution of 
effervescence. 

The decomposition of one ounce of zinc, will produce 
six hundred and fifteen cubic inches of hydrogen gas. 

A glass filled with the gas, may be removed from the 
trough, with the mouth still downward, and a lighted taper 
carried quickly under it, when a slight explosion will be 
observed. The flame will pass up in the jar, and in a few 
seconds all the gas will be consumed. 

Carry the lighted taper, quickly, above the burning sur- 
face, in order to prove that hydrogen does not support 
combustion; for it will be extinguished as soon as it 
passes above the flame, and be rekindled, as often as it is 
brought down to the burning surface. 

A light balloon may be filled with the gas, when it will 
ascend to the ceiling. 

EXPERIMENT XI. 
PHILOSOPHICAL CANDLE. 

Any common bottle may be used for this experiment. 
Put some zinc into the bottle, and pour on diluted sul- 
phuric acid. The gas should be allowed to escape for a 
few moments before the cork is introduced, in order to 
avoid an explosion. 

EXPERIMENT XII. 
HYDROGEN BY CONVENIENT METHOD. 

Put some zinc and diluted sulphuric acid (as in other' 
expei'iir.cnts) in a tall glass, and cover. When it has 



102 AGRICULTURAL CHEMISTRY. 

accumnlated for a short time, on removing the cover and 
quickly applying a taper, a slight explosion will result. 

This may be several times repeated while the gas is gen- 
erating from the same material. 

This experiment is one of the most convenient and sim- 
ple, and the means for its introduction are nearly always 
at hand. It is quite sufl&cient to illustrate the burning 
properties of hydrogen. 

EXrERIMENT XIII. 
PREPARATION OF CARBONIC ACID. 

Use the same apparatus as for generating hydrogen. 
(See fig. 10.) 

Put some one of the carbonates (chalk is the most con- 
venient) into the flask, and add diluted chlorohydric acid, 
or any of the common acids. 

The gas is rapidly generated, and may be gathered in 
a glass over water, although a small quantity will be ab- 
sorbed by the water. 

Carbonic acid may also be gathered in a tall glass by 
displacement of air, the same as chlorine in the first ex- 
periment. 

EXPERIMENT XIV. 

TEST OF CARBONIC ACID. 

Carbonic acid is tested in the same way as nitrogen, 
(see fig. 5,) and its effect upon combustion and animal life, 
will be found to be the same. 

EXPERIMENT XV. 

POURING CARBONIC ACID. 

To prove that carbonic acid may be poured from one 
vessel to another, and that it will not support flame, 



APPENDIX. 103 

place a lighted candle in the bottom of a glass, and pour 
in the gas from another when the light will be extin- 
guished. 

EXPERIMENT XVI. 
PREPARATION OF AMMONIA. 

The muriate of ammonia and quicklime may be placed 
in a flask, and heat applied. 

That ammonia is an alkali, may be proved by placing 
in the gas a litmus paper, which has been slightly red- 
dened by an acid, when its blue color will be restored. 
The litmus may as well be reddened by carbonic acid gas. 

EXPERIMENT XVII. 

CHLORIDE OF AMMONIUM. 

Pour some aqua ammonia into a wine-glass. Dip a 
glass rod in chlorohydric acid, and carry near the ammo- 
nia, when white fumes, (chloride of ammonium,) will be 
seen to form over the o-lass. 



ANALYSIS OF MANURES AND CROPS. 



A knowledge of the results of analysis of common ma- 
nures and crops may be of much advantage to the practical 
farmer, for he will thus be enabled to see at a glance what 
are the constituents of the crop he may propose to raise 
from a given field, and thus be prepared to select such 
manures as contain the proper constituents. 



104 AGRICULTURAL CHEMISTRY. 

Plants in different localities, and of different varieties, 
are sometimes found to contain a variable quantity of their 
common materials. 

The first point to be ascertained in the analysis of soils, 
manures, or plants, is, with regard to the proportion of 
water, of organic and of inorganic matters which enter 
into their composition. 

For soils, this is best accomplished by selecting a given 
quantity, which is neither more dry, nor more wet, than 
the average in the field from which it is taken. This 
should first be carefully weighed. 

The proportion of water may be determined by the appli- 
cation of such grade of heat as will slowly expel its mois- 
ture, but will not char its organic ingredients. 

When this is completed, the mass may be again weighed, 
when the difference in weight will exhibit the quantity of 
water it contained, and what remains will be the propor- 
tion of inorganic, and of organic matter. 

The mass should now be subjected to the process of 
burning, but in such way that the ashes which result, may 
not be mixed with those produced by the fuel. 

After the burning has been completed, but a small part 
of the original mass will be left, but what remains will be 
the exact proportion of inorganic matter, while the differ- 
ence between the former and the present weight will indi- 
cate the proportion of organic material. 

This process simply reveals the proportions of these 
three constituents, without indicating with regard to the 
chemical materials which composed them. To determine 
the chemical constituents of the organic, as well as of the 
inorganic matters, requires a separate analysis. 



APPENDIX. 105 



ANALYSIS OF WHEAT* 

The average composition of wheat, including the grain 
and straw is to each 1000 : 

Grain. Straw. 

Organic matter 866 835 

Inorganic matter 17 45 

Water 117 120 

1000 1000 

The proportion of bran and flour contained in wheat 
of diiferent kinds varies considerably. The fine flour, 
which is composed of starch and gluten, with a very small 
quantity of vegetable albumen, will commonly constitute 
from 70 to 80 per cent., the middlings from 11 to 17 per 
cent., and the bran from 6 to 8 per cent. 

Results of analysis by Vauquelin of two specimens of 
wheat, one grown in France, the other near Odessa: 

Wheat. French Wheat. Odessa Wheat. 
Starch 710 578 



Gluten -| 

Albumen / 



110 145 



Sugar 47 85 

Gum 33 49 

Fixed Oil — — 

Soluble Phosphates — — 

Bran — 23 

Water 100 120 

1000 1000 

The inorganic substances contained in wheat are also 

* Access has been had to the works of Liebig. Solly, and Johnston, in 
the arrani'ement of these tables. 



106 AGEICULTURAL CHEMISTRY. 

found to vary considerably in specimens from different 
fields, even when of the same variety. Different varieties, 
when grown from like fields, are also found to vary in 
their inorganic, as well as in their organic constituents. 

Two specimens of wheat, according to an analysis by 
Way, gave the following results : 

10,000 parts of ashes respectively were found to con- 
sist of: 

WHITE WHEAT. HOPETON WHEAT. 

Grain. Straw. Grain. Straw. 

Silica 263 7050 329 6710 

Phosphoric Acid 4744 577 4444 705 

Sulphuric Acid — 331 trace 559 

Lime 339 353 821 444 

Magnesia 1405 329 967 327 

Peroxide of Iron 67 14 8 154 

Potash 2991 1276 3214 1003 

Soda 187 68 214 85 

It is apparent that data of this kind will indicate the 
quantity of each substance taken off from a field by each 
crop which is raised from it. 

ANALYSIS OF BAELEY. 

The kinds of materials of which barley is composed are 
about as follows : 
Of the grain : 

Organic matter 825 

Inorganic matter 25 

Water 150 

1000 

The proportion of each substance, when produced with 
and without manure is as follows : 



APPENDIX. 107 

Barley. No Manure. Manure. 

Starch 625 596 

Gluten 29 59 

Albumen 1 6 

Sugar 50 44 

Gum 47 44 

Fixed Oil 1 4 

Soluble Phosphates 1 7 

Husk 136 136 

Water 110 105 

From two analyses of the grain by Way 10,000 parts 
of its inorganic portion, or ashes, consist of: 

I. II. 

Silica 3273 2360 

Phosphoric Acid 3169 2601 

Sulphuric Acid 79 272 

Lime 148 279 

Magnesia 745 867 

Peroxide of Iron 51 9 

Potash 2077 2743 

Soda 456 5 

Chloride of Sodium — 860- 

ANALYSIS OF OATS. 

Organic matter 872 

Inorganic matter 28 

Water 100 

1000 
The proportion of proximate elements with and without 
manure are : 

No Manure. Manure. 

Starch 600 531 

Gluten 19 44 

Albumen 2 5 

Sugar 64 50 

Gum 70 67 



108 AGRICULTURAL CHEMISTRY. 

No Mauure. Manure. 

Fixed Oil 3 4 

Soluble Phosphates 1 6 

Husk 120 170 

Water , 108 130 

Composition of inorganic matter, or aslies in 10,000 — two 
kinds used in analysis : 

I. II. 

Silica 3848 5003 

Phosphoric Acid 2646 1887 

Sulphuric Acid 110 10 

Lime 354 131 

Magnesia 733 825 

Peroxide of Iron 49 27 

Potash 1780 1970 

Soda 384 135 

Chloride of Sodium 92 7 

ANALYSIS OF POTATOES. 

The analysis of potatoes exhibit greater variety of pro- 
portions of starch, and of the azotized substances, than 
most of the materials used as foods. 

The ultimate composition of dry potato is : 

Carbon 440 

Oxygen 447 

Hydrogen 58 

Nitrogen 15 

Inorganic matter 40 

1000 
The proportion of different compounds ; two kinds being 
subjected to experiments, were found to be as follows : 



APPENDIX. 109 

Ked Potato. Sweet Potato 

Starch 155 151 

Albumen 14 8 

Gum 41 16 

Starchy Fiber 40 82 

Water 750 743 

1000 1000 

Grood potatoes are composed of 10 to 25 per cent, of 

starcli, 3 to 8 of fiber, -2 to 4 of gum, and but 1 to 2 of 

azotized matter, which is albumen, and 70 to 80 of water. 

The proportion of inorganic matter in 100,000 parts of 

dry potato tuber has been found to be as follows : 

Potash 1291 

Soda 748 

Lime 106 

Magnesia 104 

Alumina .., 16 

Oxide of Iron 9 

Oxide of Manganese trace 

Silica 27 

Sulphuric Acid 174 

Phosphoric Acid 128 

Chlorine 50 

It will be observed that the proportion of potash in the 
ashes of the potato is quite remarkable. 

ANALYSIS OF INDIAN COPvN OE MAIZE. 

Organic matter 857 

Inorganic, matter 13 

Water 130 

1000 
Dry maize contains : 
Starch 712 

^^"^^^ \ 123 

Albumen j 

Fixed Oil 90 



110 AGRICULTUEAL CHEMISTEY. 

Gum 4 

Woody matter 59 

Inorganic matter 12 

Tn 100,000 parts of the grain, 1312 parts of inorganic 
matter have been found. In the straw the proportion was 
3985. These were : 

Grain. Straw. 

Potash 200 189 

Soda 250 4 

Lime 35 652 

Magnesia 128 236 

Alumina 16 6 

Oxide of Iron trace 4 

Oxide of Manganese '... — 20 

Silica 434 2708 

Sulphuric Acid 17 106 

Phosphoric Acid 224 54 

Chlorine 8 6 

1312 3985 



NOTE. 

Complete sets of apparatus, together with chemicals, 
required for repeating the experiments described in this 
work, have been arranged by the author, in order to 
facilitate their introduction into district schools. 

The set contains a trough, retort stand, and spirit-lamp, 
together with more than thirty additional pieces. 

The whole, including chemicals, are put up in a case, 
with lock and key, in order that they may be protected 
in the school -room. This apparatus will also be found 
sufficient for illustrating most of the lessons contained in 
the common text-books on chemistry. 

The above are hept for sale ly Henry Ware, No. 7 
West Fourth street, Cincinnati. Price $20. 



GLOSSARY 



Acid— A compound, capable of iiniting witt bases, and 

thereby forming salts— turns litmus red. 
Alkali— A salifiable base, having the power of changing 

blue vegetable colors to a green. _ 

Alkiline Earth— a term applied to magnesia lime, 
etc., on account of their earthy character, and alka- 
line qualities. 'T .. 

Ammonia— An alkali which is gaseous, or aeriform, m its 
uncombined state. 

Aromatic— Odoriferous, or fragrant. 

Assimilation— The process by which bodies convert other 
bodies into their own nature, or substance. 

Azotized— Nitrogenous — containing azote or nitrogen. 

B^SE_An alkali— a substance which, by union with an 
acid, forms a salt. . 

Carbonate— A salt formed by the union of carbonic acid 
with a base. 

Chlorohydric Acid— Muriatic acid. ^ 

Combustion— The union of an inflammable substance with 
oxygen, or any supporter of combustion. 

Compost— A mixture of various manuring substances for 
fertilizing land. 

Compound— Composed of two or more elements. 

Crystalline— Consisting of crystals. 

Decomposition— Separation of a compound substance into 
its original elements. 

Demonstrate— To exhibit a process— to prove to be cer- 
tain. 

Dilute— To weaken— as an acid, or alcohol, by admixture 
of water. 

Displacement — To remove, and introduce a substitute. 



112 AGRICULTUEAL CHEMISTRY. 

Element — A body which can not be divided by chemical 
analysis. 

Evaporation — The conversion of a fluid into vapor, which 
is specifically lighter than the atmosphere. 

Evolve — To throw out — to emit. 

Exhale — To send forth, as fluid in the form of steam, 
or vapor. 

Fermentation — A chemical change in animal and vege- 
table substances, accompanied by heat and efierves- 
cence. 

Fertilizer — Enricher of soil — a manure. 

GtRAPHITE — Carburet of iron — used for lead pencils ; also 
called black lead and plumbago. 

Illustrate — To explain — to make clear. 

Inorganic — Devoid of organs. 

Nitrogenous — Pertaining to nitrogen. 

Organic — Consisting of organs — incident to life. 

Peroxide — The highest degree of oxidation of which a 
substance is capable of undergoing. 

Physical — Action of material objects distinct from chem- 
ical. 

Pith — The soft spongy substance in the center of the 
stems of plants and trees. 

Pneumatic Trough — A water trough used in experiments 
with air and gases. 

Porcelain — A fine earthenware — chinaware. 

Respiratory — Serving for respiration. 

Salt — A body composed of an acid and a base. 

SiLEX — The name of an earth of which flint is composed. 

Specific Gravity — Specific weight, as compared to air or 
water. 

Symbol — An emblem — a representation of something else. 

Tissue — A web-like structure — the elementary structure 
of plants and animals. 

Volatile — Easily evaporated. 



UBRARY 



CONGRESS 




